Motion control using electromagnetic forces

ABSTRACT

An apparatus has (a) a first component having one or more electromagnetic elements and (b) a second component having one or more electromagnetic elements and movably coupled to the first component. The second component moves with respect to the first component in a cyclical manner. The one or more electromagnetic elements of the first component interacts with the one or more electromagnetic elements of the second component during each of one or more cycles of motion of the second component with respect to the first component such that, when a constant force profile is applied to move the second component with respect to the first component, the speed of motion increases and decreases one or more times during each cycle of motion due to different levels of electromagnetic interaction between the electromagnetic elements within each cycle of motion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage application of InternationalApplication No. PCT/US2004/010236, filed Apr. 2, 2004, which claims thebenefit of the filing date of U.S. provisional application No.60/461,883, filed on Apr. 10, 2003, the teachings of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to the use of electromagnetic force/torque forcontrol of motion in unpowered apparatus and apparatus driven byelectric motors and/or other prime movers.

2. Description of the Related Art

Power control (PC) refers to control over the power generated at one ormore input to an electromechanical apparatus. Prior-art power controlmainly deals with relatively large apparatus. U.S. Pat. No. 6,380,709(Nishimura et al.) teaches an improved means of driving a motor, usingcontrolled switching of power transistors, to obtain better rotationcharacteristics. U.S. Pat. No. 6,359,410 (Randolph et al.) teaches theuse of resistive sensing to better control the maximum current appliedto the motor. U.S. Pat. No. 5,349,276 (Mezzatesta et al.) utilizes anelectronic tachometer to monitor motor speed accurately, and feed thisinformation to a control system for controlling speed reliably, in asafe-operating regime. U.S. Pat. No. 6,344,721 (Seki et al.) and U.S.Pat. No. 6,340,873 (Seki et al.) describe a semiconductor integratedcircuit for brushless motor drive control.

Power transmission control (PTC) refers to control over the powertransmitted to an electro-mechanical apparatus. Prior-art powertransmission control is also primarily targeted at relatively largeindustrial applications. U.S. Pat. No. 6,157,147 (Lin et al.) and U.S.Pat. No. 6,346,784 Lin et al.) teach the use of an eddy-current clutchto transmit power, after suitable speed translation. U.S. Pat. No.5,586,636 (Linnig et al.) teaches the use of an eddy-current clutch inconjunction with a friction clutch, to transmit power for the fan wheelof an internal/external combustion (IC/EC) engine.

Load control (LC) refers to control over the total resistive forcepresented by an electro-mechanical apparatus. Prior-art load controlincludes eddy-current and hysteresis brakes. U.S. Pat. No. 6,460,828(Gersemsky et al.) describes an eddy-current brake for a hoist, where aset of permanent magnets is selectively positioned to generate variableeddy-current force in an induction member, thus braking the hoist. Themagnets move radially outwards to increase the braking force and reducethe speed. The use of controllable braking torque by moving an inductiondisk has been used in Ferraris meters to measure power. U.S. Pat. No.6,062,350 mentions the use of conductors of varying thickness,conductivity, etc. for braking an amusement car on a track. U.S. Pat.No. 6,185,373 describes a camera with an induction brake. Here, thedevice is used to apply braking force, to stop the motion of the camerashutter, under control of the control circuitry.

Apparatus having rest states have been described in U.S. Pat. No.6,538,541 (Kralik), where a two-position switch is described, using acoil to move an armature between the two positions. U.S. Pat. No.6,532,136 (Bae et al.) describes a hard-disk drive magnetic latch, witha coil that is energized for normal operation and de-energized forparking. U.S. Pat. No. 4,706,055 (Uetsuhara) describes anelectromagnetic actuator having a member with a multiplicity of poles,in proximity with a magnet whose flux is modulated by a coil.

In various scientific demonstrations in which inductive force is used,the single mention of timing control is dropping a neodymium magnet downan inclined plane with a conductive member embedded in the plane, andslowing down of the magnet when it goes over the conductive member.Other prior art involves a pendulum consisting of a solid or slottedconducting member oscillating near a magnet, where slotting theconducting member greatly increases the stopping time.

SUMMARY OF THE INVENTION

This invention pertains to the use of electromagnetic force/torque,using possibly induction and/or hysteresis, for control of motion inunpowered (e.g., human powered) apparatus and in apparatus driven byelectric motors and/or other prime movers. The apparatus may, ingeneral, incorporate complex mechanisms. By control of motion, we meancontrol of speed of operation of an apparatus (speed), time taken by theapparatus (timing) to reach one or more significant positions (possiblybut not exclusively low-energy rest states), and forces/torques exertedon one or more sources of power to the apparatus, one or more externalloads, and/or internally between various pieces of the apparatus. Thecontrol of motion enables control of position of the apparatus. Incertain embodiments of the invention, one or more positions of theapparatus may be stable low-energy states to which the apparatus has atendency to move, which we shall refer to as rest states.

One objective of certain embodiments of the present invention is toextend the domain of electric motor speed control (and general motioncontrol—possibly unpowered or utilizing other prime movers),traditionally characterized by electronic techniques, to smallapparatus, like bubble vibration toys, paper dispensers, well pulleys,toothbrushes, display turntables, rotating lollipops, (very-low-cost)timing cams, toy racing cars, drawers, hinged objects, etc. Theseapparatus will be hereafter collectively referred to as small apparatus(SAs). These apparatus are either unpowered (e.g., human powered) ortypically but not exclusively run on one or two AA/AAA batteries,generating, e.g., a maximum of 3V initially, and less after a littleuse. This voltage is too low for cost-effective electronic control ofmotion. Indeed, at these voltages (e.g., 1.5V), even simple resistivemotor speed control techniques can become ineffective. One object ofcertain embodiments of the present invention is to achieve such control,possibly in a user-customizable fashion, at low cost. While theinvention is primarily targeted at low-cost mass-market applications,this does not limit its use in other contexts, e.g., in high-reliabilityenvironments due to simplicity of design, very high-performanceapparatus due to easy modification of apparatus static and dynamicbehavior to simplify control, design simplification of existingapparatus, etc.

Prior art in motion control, either for apparatus driven by traditionalrotating motors, linear motors, or even non-electrical prime movers likeinternal/external combustion engines (hereafter referred to as IC/ECengines), have relied primarily on a combination of:

-   -   (1) Design of the apparatus: The intrinsic design of the        apparatus—the characteristics of the prime mover, any        power-transmitting devices, any loads, and the number and        positioning of any rest states, if present, all influence the        motion of the apparatus.    -   (2) Power Control (referred to as PC): The power generated at        one or more inputs to the apparatus is modulated as desired.        Examples include pulse-width modulation/resistive control for        motors, and/or gasoline/fuel injection control for IC/EC        engines. These methods may or may not involve closed-loop        feedback, using possibly back-emf sensing techniques, speed        tachometers, etc.    -   (3) Power Transmission Control (referred to as PTC): The power        transmitted to the apparatus is modulated as required. Clutches        (friction, hydraulic, eddy-current/hysteresis, magnetic        particle) are examples. The amount of power transmitted to the        load can be modulated within limits.    -   (4) Load Control (referred to as LC): The total resistive force        presented by the apparatus is modulated as desired.        Friction/induction brakes have been primarily used for        completely stopping, or aiding the stopping process of a prime        mover, but typically have not been used for controlling speed,        during normal running of the prime mover. The primary reason        being that these embodiments of load control are dissipative        methods, and friction brakes are prone to stick-slip.

These techniques are generally applicable. They can be applied toapparatus having no preferred position (no rest state), as well asapparatus that have preferred positions (rest states). Mechanicalratcheting devices, electromagnetic relays, latches, actuators, etc. areexamples of apparatus having rest states.

The present invention can be embodied with one or both of the following:

-   -   (I) Techniques to achieve motion control (possibly with rest        states) using electromagnetic force, possibly using induction        and/or hysteresis, in various apparatus. These techniques are        based on the interaction amongst one or more magnets (primarily        permanent but can be electromagnets also), and/or conductive or        ferromagnetic strips, sheets, rods, etc. (hereafter referred to        as induction/hysteresis members), generating the electromagnetic        force. These magnets and induction/hysteresis members can be        solid, slotted, or perforated, can have various geometries,        various dimensions (length, width, height/thickness), and be of        various conductive, ferromagnetic, partially conductive,        partially ferromagnetic, or composite materials. The three forms        of these techniques, which can be used in conjunction, are:

(a) Power Control: This refers to control at the source of the power. Inmotors, the magnetic flux path geometry or properties of theinduction/hysteresis interaction members are physically changed,achieving modulation of the magnetic field and/or inducted currentsand/or forces/torques inside the machine. In general mechanisms,additionally, multiple powering sources (rotary or linear motors) arepresent, which are controlled in a co-operative manner to achievedesired motion. The state-of-art in field control, typically changes thecurrent exciting a field coil. The state-of-art of modulation ofpermanent-magnet field has not been applied to a low-cost electric motorfor controlling speed. One key idea here is varying the designparameters of the machine to achieve motion control, and can be appliedto all kinds of prime movers. For example, an IC petrol engine can becontrolled by varying the length of the stroke, using an appropriatemechanism.

(b) Power Transmission Control: This refers to control in the powertransmission chain. In rotating systems, the electromagnetic forcetransmission is controlled by varying the magnetic flux path and/orinduction/hysteresis member geometry, and is a generalization ofelectromagnetic clutches. In general mechanisms, additionally,force/torque can be transmitted through multiple portions of themechanism, and the mechanism is designed to make these multipletransmitted force/torques to be complementary.

(c) Load Control: Control of electromagnetic load here is also primarilybased on the geometry and relative positioning of magnets and/orinduction/hysteresis members. Both the geometry and the relativepositioning of the magnet or magnets and/or the induction/hysteresismembers can optionally be changed. In general mechanisms, additionally,multiple loading elements can be present, which are designed to jointlymeet a desired loading criterion.

The amount of control exerted on the apparatus by the three techniquescan be constant with time, periodically varying, or aperiodicallyvarying, as desired by the user, and possibly changeable at the time ofusage of the apparatus. The invention can be used in conjunction withall existing methods of motion control also. The invention isexcellently suited for applications wherein low cost is primary, as itis, in a major embodiment primarily but not exclusively, a passivemethod, and does not require expensive poweredmicroprocessor+servo/similar devices.

-   -   (II) Application of aforesaid motion control technique to        apparatus that have hitherto not used even existing techniques        of motion control, and the realization of new functionality in        the aforesaid apparatus, as well as realization of new apparatus        utilizing our techniques.

While the invention is primarily targeted at low-cost mass-marketapplications, this does not limit its use in other contexts, e.g., inhigh-reliability environments due to simplicity of design, veryhigh-performance apparatus due to easy modification of apparatus staticand dynamic behavior to simplify control, design simplification ofexisting apparatus, etc.

According to certain embodiments, the present invention is an apparatuscomprising (a) a first component having one or more electromagneticelements and (b) a second component having one or more electromagneticelements and movably coupled to the first component. The secondcomponent is adapted to move with respect to the first component in acyclical manner. The one or more electromagnetic elements of the firstcomponent are adapted to interact with the one or more electromagneticelements of the second component during each of one or more cycles ofmotion of the second component with respect to the first component suchthat, when a constant force profile is applied to move the secondcomponent with respect to the first component, the speed of motionincreases and decreases one or more times during each cycle of motiondue to different levels of electromagnetic interaction between theelectromagnetic elements within each cycle of motion. As used in thisspecification, the term “force profile” is intend to refer to eitherforce or energy (e.g., for certain powered applications).

As used in this specification, the term “cycle” can refer to a “unit” ofmotion of the apparatus. For example, in an embodiment where the secondcomponent rotates with respect to the first component, a cycle can referto a 360-degree rotation. Note that, in some applications, such as thoseinvolving a screw, a 360-degree rotation of the screw is accompanied bya translation of the second component (e.g., the screw) with respect tothe first component. Thus, in general, a cycle of motion can but neednot return the two components to their exact same relative positions. Inan embodiment primarily involving translational motion, such as adrawer, depending on the context, a cycle could refer to moving thesecond component from a start position to an end position (e.g., fromthe drawer in its closed position to the drawer in its open position),or a cycle could refer to moving the second component from a startposition to an end position and then back to the start position (e.g.,opening and then closing the drawer).

In at least one embodiment, the levels of electromagnetic interactionare dependent on the direction of the motion of the second componentwith respect to the first component. For example, the levels ofelectromagnetic interaction associated with a forward cycle of themotion may be different from the levels of electromagnetic interactionassociated with a reverse cycle of the motion.

In at least one embodiment, there exists at least one non-constant forceprofile, such that, when the at least one non-constant force profile isapplied to move the second component with respect to the firstcomponent, the speed of motion is constant during each cycle of motiondue to the different levels of electromagnetic interaction between theelectromagnetic elements within each cycle of motion.

In at least one embodiment, when an impulse force is applied to move thesecond component with respect to the first component, the speed ofmotion increases and decreases one or more times during a first cycle ofmotion due to the different levels of electromagnetic interactionbetween the electromagnetic elements within the first cycle of motion.For example, when the impulse force is applied to move the secondcomponent with respect to the first component, the second component maymove with respect to the first component in two or more contiguouscycles of motion, wherein the speed of motion increases and decreasesone or more times during each cycle of motion due to the differentlevels of electromagnetic interaction between the electromagneticelements within each cycle of motion.

In at least one embodiment, at least one electromagnetic element has anon-uniform surface texture that is matched to a surface to which it isattached.

In at least one embodiment, the electromagnetic elements are all passiveelectromagnetic elements, and at least one electromagnetic element is apermanent magnet. As used in this specification, the term “passiveelectromagnetic element” refers to an element exhibiting one or more ofpermanent magnetism, electrical conduction, and magnetic hysteresis.Magnetic hysteresis refers to the ability of an element to exert forceson other electromagnetic elements in time-varying magnetic fields, e.g.,due to the creation of induced magnetism within the hysteresis element.Hard iron is an example of a material that exhibits magnetic hysteresis.In theory, a passive electromagnetic element can exhibit any combinationof these three properties. For example, in addition to magnetichysteresis, hard iron exhibits electrical conduction and, in certaincircumstances, permanent magnetism.

In at least one embodiment, at least one electromagnetic element is anelectromagnet.

In at least one embodiment, the second component has one or morelow-energy positions during each repetition of motion relative to thefirst component, wherein each low-energy position corresponds to a peakin overall attractive interaction level between the electromagneticelements. For example, the second component may have two or morelow-energy positions that are not equally spaced within each cycle ofmotion. For applications where the motion is rotation, the spacing oflow-energy positions relates to angular distance between low-energypositions. For applications where the motion is translation, the spacingrelates to linear distance between low-energy positions along the pathof motion between the components. Note that, depending on the particularapplication, the path of motion may be straight or curved.

In at least one embodiment, the apparatus further comprises one or moreprime movers adapted to cause the second component to move with respectto the first component. At least one prime mover may be anelectromechanical motor. For example, the motor may be driven by a DCvoltage of about 3V or less, such as a battery-powered motor.

In at least one embodiment, the at least one prime mover is adapted tocause multiple contiguous cycles of motion having a substantiallyconstant steady-state period of motion for each cycle of motion, duringwhich a profile of the speed of motion within each cycle of motionrepeats from cycle to cycle. The profile of the speed of motion mayinvolve the speed of the second component increasing and decreasing withrespect to the first component within each cycle. Electromagneticinteraction between the first and second components may reducevariations of speed within the profile of the speed of motion otherwisecaused by the prime mover.

In at least one embodiment, the apparatus has only one prime mover.

In at least one embodiment, the apparatus has two or more prime movers.

In at least one embodiment, each prime mover is adapted to move adifferent component with respect to the first component Each prime movermay be adapted to move the second component over a different portion ofeach cycle of motion.

In at least one embodiment, the first and second components are part ofa prime mover, wherein the prime mover is adapted to move the secondcomponent with respect to the first component.

In at least one embodiment, the second component is adapted to move withrespect to the first component as a result of external force applied tothe second component by a user of the apparatus. The second componentmay be adapted to continue to move with respect to the first componentafter the external force has been removed.

In at least one embodiment, the apparatus is adapted to enable a user ofthe apparatus to alter the interaction levels between the first andsecond components. At least one of the electromagnetic elements may beadapted to be removed from the apparatus by the user to alter theinteraction levels between the first and second components. Theapparatus may enable the user to change the distance between the firstand second components to alter the interaction levels between the firstand second components.

In at least one embodiment, at least one of the electromagnetic elementsin one of the components is a magnet, and at least one of theelectromagnetic elements in the other component is an interactionelement. The interaction element has a material that exhibits at leastone of electrical conductivity and magnetic hysteresis. The electricalconductivity or magnetic hysteresis or both of the material varies withposition over the interaction element, such that, as the secondcomponent moves with respect to the first component, the magnet inducesat least one of eddy currents and hysteresis forces in the interactionelement that vary in intensity during each cycle of motion.

In at least one embodiment, the interaction element has one or morecutouts, each cutout corresponding to a position of local minimuminteraction level between the electromagnetic elements. For example, theinteraction element may have a plurality of cutouts, wherein at leasttwo of the cutouts have different dimensions resulting in differentlocal minimum interaction levels and different speeds of motion overeach cycle of motion.

In at least one embodiment, the motion is rotation of the secondcomponent relative to the first component, and the variation in theelectrical conductivity or magnetic hysteresis or both of the materialresults from the interaction element having a non-circular cross-sectionwith respect to a plane perpendicular to the axis of rotation of thesecond component with respect to the first component, such that theinteraction level between the magnet and the interaction element variesover each cycle of rotation.

In at least one embodiment, the composition of the interaction materialvaries with position within the interaction element.

In at least one embodiment, each component has one or more magnets whoseinteraction levels vary over each cycle of motion.

In at least one embodiment, the second component is rotatably coupled tothe first component such that the cycle of motion corresponds to acomplete rotation of the second component with respect to the firstcomponent.

In at least one embodiment, the second component is rotatably coupled tothe first component such that the cycle of motion corresponds to apartial rotation of the second component with respect to the firstcomponent.

In at least one embodiment, the second component is slidably coupled tothe first component such that the cycle of motion corresponds to acomplete reciprocation of the second component with respect to the firstcomponent, where the sliding motion may be along a substantiallystraight line or along a curved path, e.g., that lies substantiallywithin a plane.

In at least one embodiment, the second component is slidably coupled tothe first component such that the cycle of motion corresponds to apartial reciprocation of the second component with respect to the firstcomponent.

In at least one embodiment, the apparatus further comprises at least onemore component, wherein the first, second, and at least one morecomponents form at least two pairs of corresponding components, wherein,within each pair, one component is adapted to move with respect to theother component.

BRIEF DESCRIPTION OF THE DRAWINGS

Other aspects, features, and advantages of the present invention willbecome more fully apparent from the following detailed description, theappended claims, and the accompanying drawings in which like referencenumerals identify similar or identical elements.

FIG. 1: Key challenge in certain embodiments of the invention: apparatusdriven by slowly varying source of low-voltage power (about 1-3V)energizing an electric motor, or apparatus driven by human power(unpowered apparatus), where invention controls motion of apparatus.

FIG. 2: (a) Magnet Monopole (b) Magnet Dipole inducing closededdy-current loop E_2_300 (top view) (c) Eddy loop closed through diode(nonlinear device) Di_2_110 (d) Showing multiplication of inducedvoltages by series connection of voltages induced in insulated parts.

FIG. 3: (a) Magnet M_3_100 near Induction/Hysteresis Member I_3_200 (b)Magnet M_3 _100 farther away, reducing field.

FIG. 4: (a) Magnets close to each other (b) Magnets farther away,reducing field.

FIG. 5: (a) Air-Gap Ag1_5_300 modulation by moving magnets M_5_100 andM_5_200 and back-iron further away (b) Air-gap modulation by changingreluctance of auxiliary Air-Gap Ag2_5_310, by moving pole piece P_5_310.

FIG. 6: Combined Induction/Hysteresis Member (Copper Disk I_6_200 withfour steel inserts—one is H_6_210) in the vicinity of stationary magnetassembly M_6_100. Some/all of the steel inserts can be replaced bymagnets (not shown).

FIG. 7: Induction Disk, Magnet, and Contacting Bearing (a) 3-D View (b)Axial Cross Section.

FIG. 8: Field weakening by changing the relative distance between polepieces (a) Strong Field, since Pole Pieces P_8_300, P_8_310 are closetogether (b) Weak Field, since Pole Pieces P_8_300, P_8_310 are farapart Both (a) and (b) are views looking axially directly at the rotor.The physical motion of the pole pieces can be replaced by alternativemeans as outlined in Section A.

FIG. 9: Changing interaction between field and rotor (a) Fullinteraction (b) Partial interaction. The figure shows axial crosssection of the rotor and stator.

FIG. 10: Modified Motor with torque which changes within a single cycle,useful for timing control. (a) Rotor R_10_300 aligned with pole piecesP_10_310: Low airgap, High flux, High torque & speed (b) Rotor R_10_300perpendicular to field: High airgap, Low flux, Low torque & speed (c)Cylindrical non-ferromagnetic rotor R_10_320, with effective magneticfield similar to (b), due to ferromagnetic insert F_10_400 at rightangles to main flux path. This is a low Torque configuration. (d)Cylindrical non-ferromagnetic (with ferromagnetic insert F_10_410) rotorR_10_330, with asymmetric magnetic field, and variable speed/torque dueto dissimilar pole pieces.

FIG. 11: Gear Train with customizable speed-torque characteristics(axial cross-section view). Force/torque is transmitted from drivingaxle DGA_11_310 to driven axle DNA_11_320, using customizableinduction/hysteresis force generated in induction/hysteresis memberIM_11_200 by relative motion of magnets M_11_100 with respect toIM_11_200.

FIG. 12: Gear Train with customizable speed-torque characteristics, withcontacting bearing CB_12_330.

FIG. 13: Gear Train with customizable speed-torque characteristics,using magnetic force transmission due to autonomously magnetic members.Repulsive force between like (North) poles pushes driven axle forward(a) Side View (b) Front View looking on axle DGA_13_310 (Large MagnetsM_13_110 _(—) b omitted from (b) for clarity).

FIG. 14: Basic Motion Control using controllable induction (a) HighSpeed (b) Medium Speed (c) Low Speed. (d) Magnet M partially outsidedisk, reducing induction and causing speed increase. Speed is controlledby varying the position of a field generating device (magnet M_14_100),with respect to axis of rotation A. Alternative structures can be usedfor magnet M (Section A).

FIG. 15: (a) Low Speed, with M_15_100 close to disk (b) Higher speedwith M_15_100 far from disk. (c) Highest speed with M_15_100 farthestfrom disk.

FIG. 16: Induction Disk showing multiple magnets, with flux returnpaths.

FIG. 17: (a) Magnets facing each other with controllable airgap (b) Onemagnet in reluctance circuit, but not in air-gap of induction disk.Induction disk not shown (see FIG. 16).

FIG. 18: Induction Drum with Magnets/Magnet Assemblies.

FIG. 19: (a) Alternative Structure corresponding to FIG. 17 showingbearing supporting disk, with magnets part of bearing structure. (b)Cross Section View of (a).

FIG. 20: (a) Magnet assembly M_20_100 over conducting/ferromagnetic disksector, maximum torque (b) M_20_100 at periphery ofconducting/ferromagnetic sector, lower torque (c) M_20_100 over cutoutsector, close-to-zero inductive/hysteresis torque.

FIG. 21: Timing Control Induction Disk with three cutouts.

FIG. 22: Timing Control Induction Disk, with symmetric cutouts, andmultiple magnets, to yield zero net force, but nonzero torque.

FIG. 23: Timing Control Induction Disk with Slotted/Perforated AreaSPA_23_300. Braking Force/Torque intermediate between full cutout andsolid area

FIG. 24: Programmable Timing Control Disk showing placement of slotsSL_24_300 and induction members IM_24_200 and IM_24_210 (conductive disksectors), which can be selectively inserted into slots to programmablycontrol timing, using induction from the field of magnet assemblyM_24_100/M_24_110. The proper fastening of conductive disk sectors tothe frame, in a removable fashion, can be done by a variety of meanswell known in the art. The slot and conductive disk sector pattern isrepeated (possibly with changes) on frame FR_24_310 as desired.

FIG. 25: Rigid link R_25_300 is enhanced by magnetic and/or inductionand/or hysteresis members and has electromagnetic interaction withanother similar but not necessarily identical rigid link R_25_310. Rigidlink R_25_300 is connected by three revolute joints to other links.Rigid Link R_25_310 is connected to R_25_300 at revolute joint J_25_320on R_25_300 (all details in R_25_310 are not shown). Electromagneticforce results from interaction between R_25_300 and R_25_310.

FIG. 26: Exemplary Revolute Joint enhanced by the invention: (a) Pin andHousing together Pin P_26_300 is attached to Link 1_26_310 (not shown).Pin Housing PH_26_320 is attached to Link 2_26_330 (not shown). (b)Magnetization of exemplarily hollow pin P_26_300 (c) Magnetization ofHousing PH_26_320. In general poles need not be equally spaced, and pinand housings need not be concentric in general.

FIG. 27: Two stable (a), (b) and two unstable (c), (d) positions ofmagnetic pin P_26_300 and pin housing PH_26_320, offset by one quarterrevolution each.

FIG. 28: Prismatic pair with magnetic interaction. Induction and/orhysteresis members can optionally be used on either Link1_28_300 and/orLink2_28_310. The spacing between magnets and/or induction and/orhysteresis members need not be uniform. The electromagnetic energy atany of the maxima/minima need not be the same. An exemplary embodimentof these ideas is the Extendible Tether of FIG. 59.

FIG. 29: Screw pair with controllable rest positions and possiblynon-uniform damping torque. M_29_100, M_29_110 are attached to SH_29_300by means not shown.

FIG. 30: Stepper Mechanism with Powered Pins and links. The sequencingof the powered coils is under the influence of the control circuitryand/or the mechanisms motion itself, analogous to brushless motors andcommutated motors. In this illustration, the powered coils are all onlink R_30_300, but this is not necessary in general. Drawing might notbe to scale.

FIG. 31: 4-bar linkage with magnetic/induction/hysteresis interactionbetween links, with capability to form mechanical logic. R_31_300 is thefixed link, R_31_310 is the input link, and R_31 _320 is the outputlink. Prismatic Pair P_31_400 may include induction members and magnetsnot shown.

FIG. 32: Power Control for a Reciprocating Mechanism (a) MaximumForce/Torque position (b) Minimum Force/Torque Position.

FIG. 33: Power Transmission Control for a Reciprocating Mechanism: (a)The drive pin DP2 is omitted (or modified), and auxiliary constraintskeeping connecting rod CR_33_320 in the vicinity of reciprocating shaftRS_33_330 are present. Magnet M_33_100 (or Magnets M_33_100) areattached to CR_33_320. Inductive force is produced in RS_33_330, due toslip between CR_33_320 and RS_33_330. (b) Modification of drive pinDP2_33_340. A slot is cutout in RS_33_330, in which DP2_33_340 canslide. The slot serves to constrain CR_33_320 to be in proximity withRS_33 _330. No vertical force is transmitted through the slot. Verticalforce is due to induction in RS_33_330 due to field from magnet M_33_100(or magnets M_33_100).

FIG. 34: Reciprocating mechanism with Load control.

FIG. 35: Mechanism Timing Change by induction force.

FIG. 36: Vibration Minimization using Load control using magnets for anIC-engine Magnets M_36_100 and M_36_110 (below M_36_100 on mountingMO_36_400) have like poles facing each other, and are so arranged tocome close to each other at the end of the power stroke (with theflywheel F_36_300 as shown), absorbing energy from the prime mover (thegas force from the piston). During continued rotation of F_36_300,M_36_100 and M_36_110 repel each other, releasing energy, compensatingfor the lack of power during the exhaust stroke. The geometry ofM_36_100 and M_36_110, and the engine may differ from the illustration.

FIG. 37: Bubble Vibration Toy, with circular soap film frame SF_37_300.

FIG. 38: Variants of Bubble Vibration toy, showing different kinds offrames, and different modes of excitation (translation+rotation),possibly using auxiliary frames. (a) Rectangular Soap Film Frame. (b)Soap Film Frame SF showing higher order modes, which are madenon-degenerate by projection P_38_300 from SF, which forces a node (zeromotion) and unambiguously determines the angular position of theresonant mode. (c) Cubical Soap Film Frame. (d) Soap Film Frame SF,Angularly Vibrating around axis. (e) Stationary Soap Film Frame SF,excited by auxiliary frame angularly vibrating around axis. The shape ofthe auxiliary frame may be different from illustration. Both frames maybe excited. In general, one or more frames may be excited using one ormore excitation waveforms. The resonant modes shown in these figures areonly illustrative. The modes obtained in practice may differ from thoseillustrated.

FIG. 39: Soap Film Frame Assembly having multiple sections, of differentshapes and dimensions, and different resonant frequencies. Changing thevibration frequency will selectively excite different sections, changingthe vibration pattern visible to the viewer.

FIG. 40: Paper Dispenser with Inductive Speed Control (ExemplaryEmbodiment).

FIG. 41: Well Pulley Inductive Speed Control (Exemplary Embodiment).

FIG. 42: Rotating Display Turntable, whose speed can be controlled usinginduction device.

FIG. 43: Rotating Display Turntable, whose speed can be controlled usinginduction device, with cutout.

FIG. 44: Rotating Display Turntable, whose speed can be controlled usinginduction device, with cutout, which can be optionally programmable

FIG. 45: Rotating Doll, with speed programmably controllable, possiblyin a non-uniform fashion.

FIG. 46: Rotating Lollipop with speed programmably controllable possiblyin a non-uniform fashion.

FIG. 47: (a) Timing Control Induction Disk, used as a timing CAM (b)Angular Position as a function of time, for a constant position ofmagnet M_47_100, relative to axle A_47_400. Braking Force/Torque inslotted area SL_47_300 is intermediate between full cutout and solidarea (c) Auxiliary mechanism Me_47_500 simultaneously moving magnetM_47_100 outwards relative to axle A_47_400 (d) Angular position as afunction of time resulting from the motion of (c), showing periodicvariations corresponding to rotation, and a general slowing down due tomovement of magnet M_47_100 (e) Pulsating Force/Torque corresponding to(d). The force/torque profile is illustrative only and the achievedforce versus time profile may differ from illustration.

FIG. 48: Powered Toothbrush with speed control SC_48_400 using speedcontrol as per Sections A to E. ME_48_300 is the brush mechanism,converting rotation of the motor to the brushhead'srotation/oscillation.

FIG. 49: Drawer with induction brake to prevent excessively violentopening/closing. (a) Top View (b) Side View of one embodiment, includinggearing mechanism (gearing details not shown).

FIG. 50: CD mechanism incorporating induction braking to prevent violentejection.

FIG. 51: Apparatus using a hinge, enhanced to reduce excessivelyhigh-speed operation.

FIG. 52: Induction Speed Limiting for bin lid. Induction Memberpositioned near edge of lid for maximum speed.

FIG. 53: Induction Speed Limiting with gear for bin lid.

FIG. 54: Induction Speed Limiting with multiple gears for bin lid.

FIG. 55: Magnetically Adjustable Pedestal, showing two pot platforms,whose height/angular position can be adjusted.

FIG. 56 (a) Ferromagnetic Grooved pedestal, and (b) Matching projectionson magnet/magnets attaching the platform(s) to the pedestal. The matchedgrooves and projections enhance holding force, and prevent motion in anydirection. The ferromagnetic pedestal can be spherical, or any othershape, with grooves on its surface. Magnet/magnets holding the platformsto the pedestal, have matching projections on their surface.

FIG. 57: Magnetic Cabling Clip holding cables to ferromagnetic object(e.g. computer cover).

FIG. 58: Top View of Carom Board, showing magnets M_58_100 beneathboard, and induction members in the striker S_58_310 and/or piecesPi_58_300.

FIG. 59: Extensible Tether with Induction Braking (front view).

FIG. 60: Airplane with Maglev, Magnets on Ground, and Induction MemberI_60_200 on aircraft. Induction Member may be inside craft, lowered outof craft during landing, or may be integrated with fuselage itself.

FIG. 61: Electromagnetic Manipulator lifting exemplarily screws andtightening them in object (not shown).

DETAILED DESCRIPTION

The present invention extends the domain of electric motor speed control(and general motion control using possibly other prime movers orunpowered motion), traditionally characterized by electronic techniques,to small apparatus (SAs). Primarily but not exclusively, physical motionof appropriately shaped, magnetic flux-producing devices, andappropriately shaped, interacting devices (primarily but not exclusivelymagnets and/or conductive and/or ferromagnetic portions of theapparatus) is used for the control. In particular, we describemodifications of electric motors, induction clutches and brakes, andelectromagnetic actuators, yielding new devices, which can be used forcontrolling motion of a large variety of apparatus.

Our techniques offer the ability to perform detailed control of motiontiming in mechanisms, and arbitrary timing functions can be generated.We also describe new application of our devices in existing apparatus,as well as new kinds of apparatus, yielding hitherto unrealizedbenefits.

Certain embodiments of the invention use a combination of Power Control(PC), Power Transmission Control (PTC), and Load Control (LC). Existingimplementations of these techniques are in general too expensive andunsuited (due to power requirements, etc.) for the targetedapplications. The invention offers new implementations of PC, PTC, andLC overcoming these limitations. Even in applications where the existingtechniques are suitable, our invention, whether used singly or inconjunction with existing techniques, can offer benefits in terms ofsimplicity of operation, high reliability, fail-safeness, etc.

Power control is realized typically by pulse-width-modulation systems inthe state-of-art, and the invention realizes many of the benefits ofpulse-width-modulation, without using electronics. This is done bygeneralizing the geometry of electrical prime movers to include possiblymultiple non-cylindrical power generating sections, connected togetherby arbitrary mechanisms, with arbitrary rest states. The techniques ofachieving motion control without using electronic control can bedirectly applied to other prime movers also. For example, an IC/ECengine can achieve speed control without fuel injection control bychanging the stroke of the engine, using an appropriate mechanism.

Power transmission control is realized by electromagnetic clutches inthe state-of-art, and the invention in certain embodiments is ageneralization of electromagnetic clutches. Even when certainembodiments of the invention can be directly classified aselectromagnetic clutches (eddy-current and/or hysteresis clutches), theinvention distinguishes itself from the state-of-art in (a) the novelgeometry of the clutch, (b) the novel (very low cost) programmability oftransmitted force/torque, and (c) the application to low-cost apparatus,which traditionally have not used them.

Load control is realized in the state-of-art using induction/hysteresisbrakes, and the invention in certain embodiments is a generalization ofinduction/hysteresis brakes. Even when, certain embodiments of theinvention are directly classifiable as induction brakes, the inventiondifferentiates itself from the state-of-art in (a) the duration ofapplication of the induction force/torque, which is typically held onduring the normal operation of the apparatus, and changing the magnitudeof the induction force/torque changes the apparatus/prime mover speed,(b) the new methods of generating the controllable inductionforce/torque, (c) the utilization of these new methods to change thespeed/timing/forces/torques, in a single cycle of apparatus operation,possibly in a programmable fashion, (d) the exploitation of the propertythat the induction force is velocity dependent, to provide automaticspeed control feedback, and (e) the application to low-cost apparatus,which traditionally have not used them.

The invention has broad applicability in the field of design of generalmechanisms. The current state-of-art requires close attention to be paidto the interaction of kinematics (path generation, etc.) and dynamics(velocity/timing/force) in mechanism design.

The invention can substantially decouple these two problems. Anadditional novel feature of certain embodiments of the invention is thesystematic exploitation of rest states, appearing when multiple parts ofthe apparatus are magnets or ferromagnetic material. From one point ofview, our work can be regarded as generalizations of both electricmachines and general mechanisms, to yield a new class of devices,hereafter called electrical mechanisms.

While the invention may be targeted at low-cost mass-marketapplications, this does not limit its use in other contexts, e.g., inhigh-reliability environments due to simplicity of design, veryhigh-performance apparatus due to easy modification of apparatus staticand dynamic behavior to simplify control, design simplification ofexisting apparatus, etc.

We shall first describe the techniques of the invention in the order ofPower Control (PC), Power Transmission Control (PTC), and then LoadControl (LC), for rotating apparatus powered by electric motors. Then,we shall generalize our techniques to general mechanisms. We describeour techniques with reference to both apparatus without rest states, andthose with rest states. Finally, we describe apparatus in which ourtechniques have been applied, and the resultant novel functionality.Much of the discussion will center on Load Control (it can be applied tounpowered devices also), but the ideas are equally applicable to PowerControl and Power Transmission Control.

We shall primarily discuss electromagnetic induction-based techniques,but the techniques can be directly translated into hysteresis-basedtechniques, as well as techniques based on magneticattraction/repulsion, and are additionally stated by implication of thisstatement here. Where appropriate, we shall mention differences(Sections A[4] and A[5]). We describe our techniques primarily in termsof fixed magnets (permanent or electromagnets) inducing currents inmoving induction members, but our methods are equally applicable whenthe magnets move and the induction members are stationary, or both moverelative to each other. Applicability of our techniques to these casesis stated by implication of this statement here. In passing, we notethat any electromagnetic interference (EMI) generated by the apparatuscan be handled by methods well known in the state-of-art.

To begin, we briefly indicate the challenges in motion control in thetargeted apparatus, followed by some generic issues in controllingmagnetic flux.

Motion Control for Battery-Operated & Unpowered Devices

The invention can be (but is not exclusively) targeted at low-costapplications like bubble vibration toys, paper dispensers, displayturntables, rotating dolls, rotating lollipops, toothbrushes, racingcars, drawers, etc. Speed control in these devices should typically besmooth, but not necessarily set to an accurate value.

In certain embodiments of these applications, the apparatus is eitherunpowered (e.g., paper dispensers, drawers) or uses an electric motorrunning off one or two (or a few) 1.5V AA or AAA batteries, as inFIG. 1. The available power hence ranges from 1V to 3V (or a few volts),precluding any cost-effective electronic control of motion. Note thatpower MOSFETs do not even turn on at these voltages. Electrical controlis limited to mechanical on-off switching. Speed control using resistorsreduces the available motor power, requires one or more power resistors,and is especially prone to stick-slip at low speeds. In principle,winding current control using transistors driven by varying base drivecan be attempted, but is susceptible to varying transistor current gainand is again prone to stick-slip at low speeds. In contrast, our passivemethod consisting of application of controllable electromagneticforce/torque does not require any electronics, has no stick-slip incertain embodiments, can be implemented with low dissipation by a properchoice of motor impedance, works equally well in unpowered applications,and can be implemented at very low cost. The method is quite general andcan be equally applied to apparatus utilizing other control techniqueslike pulse-width-modulation, to systems using higher voltage thanpreviously described, to systems using other prime movers like IC/ECengines, and to systems where lowering of cost is not necessarily amajor objective. The method works using a combination of Power Control,Power Transmission Control, and Load Control.

Additionally, the use of motion control itself, and particularlymagnetic/induction/hysteresis motion control in unpowered apparatus isnew.

A. Generic Methods of Controlling Magnetic Flux, Induced Currents,Hysteresis, and Force/Torque

This invention generates controlled forces/torques, by controlling oneor more of (a) the magnetic flux in a desired region and (b) the inducedcurrents/field hysteresis due to the flux interacting withinduction/hysteresis members (conductors/ferromagnetic material) in anydesired region. Changing either the flux and/or inducedcurrent/hysteresis changes the force/torque. In all that follows,mechanical means (e.g., screws, sliders, etc.) of performing any desiredmotions of either the flux-generating or the induction/hysteresismembers, are assumed to be available and will not be described. We firstconsider induction methods, and then outline differences between the useof induction members and hysteresis members, and multiple flux sources.

[1] Control of Magnetic Flux

A first approximation for the magnetic flux in a region is given by themagneto-motive-force (mmf) divided by the reluctance of the pathstraversed by the magnetic flux. Changing either the mmf or thereluctance will change the magnetic flux. In apparatus we consider, themagnetic flux is predominantly but not exclusively produced by permanentmagnets (typically high-strength neodymium magnets). In this case, themmf in a given apparatus is fixed by the geometry, size, and strength ofthe permanent magnets used. If electromagnets are used, then the mmf andhence the flux can be changed by changing the current in the coils. Thismethod can be used in conjunction with all the techniques mentionedhere. The reluctance of the flux path, however, can be changed, bychanging any air-gaps present. Additionally, in regions of non-uniformmagnetic fields, changing the position of the region will change theflux and/or the induced currents and forces due to it. The embodimentsare classified according to (1) the number of magnets, (2) the presenceof flux return path (back-iron), and (3) the presence of conductivematerial (induction members) in which eddy-currents leading to inductiveforces are generated.

Unless otherwise mentioned, for simplicity of illustration, we chose acylindrical disk magnet structure, axially magnetized (one circular faceis north, the other south), in all that follows (see M_2_100 in FIG. 2(a)). In many embodiments, the magnet's poles and flux paths are designedas dipoles (i.e., a structure with unlike poles facing the same face ofan induction/hysteresis member), to force the induced currents to followtight closed loops. In FIG. 2( b), magnet M_2_100 has north pole facingup, and magnet M_2_110 has south pole facing up, causing eddy loopE_2_300 due to rotation of nearby induction disc I_2_200 around axleA_2_210). Eddy loops can be created using separate current return paths.If the current return paths are non-linear, then the force/torqueexhibits non-linear characteristics. For example, the stationary diodeDi_2_110 in FIG. 2( c) is arranged with its terminals contacting thesurface of induction disc I_2_200 (e.g., through brushes), to provide acurrent return path near magnet M2_100. Di_2_110 can also be oninduction disk I_2_200, and in this case is arranged to avoid cancelingelectromotive force being induced in it. In this case, the force becomesdirection-dependent. In the direction of rotation where the voltage isopposed by the diode, current cannot flow through a closed path, andinduced force/torque is low. In the other direction, at low speeds, theinduced voltage is too small to fire the diode, resulting in a lowcurrent. As speed increases, the induced voltage fires the diode,closing the eddy-loop, resulting in a large current/force/torque. Thisresults in a force/torque characteristic that exhibits a “diode-like”nonlinearity. The “breakpoints” can be changed by using diodes ofdifferent bandgap (germanium, silicon, etc.). Even for the same diode,the breakpoint can be modulated by series/parallel connecting theinduced voltages at multiple locations—insulated from each other (Fig.FIG. 2( d)). In FIG. 2( d), the induction disk I_2_210 is divided intofour insulated sectors S1 to S4, and voltages are induced in each sectorby four magnet assemblies. These four voltages are picked up by brusheswell known in the state-of-art (not shown for clarity) and seriesconnected before being connected to diode Di_2_120. Thus, the voltageacross the diode terminals is four times the voltage induced by any onemagnet, causing it to fire at a lower speed. The use of two diodesoppositely oriented offers low force in either direction before eitherdiode fires, and high force as speed is further increased in eitherdirection. Series connection of voltages in different sectors may bedifferent for the forward and reverse directions, offering even morecontrol of current/force/torque with respect to speed. The invention isequally valid for such magnets as well as for arbitrary magnetstructures and current loop paths.

1. Single magnet, no flux return path: In FIG. 3, the field/flux iscontrolled by varying the position of the magnet M_3_100 relative to thedesired region (of interaction), which exemplarily can be aninduction/hysteresis member, e.g., I_3_200. M_3_100 is further fromI_3_200 in FIG. 3( b) than in FIG. 3( a).

2. Multiple Magnets, no flux return path: Here, in addition to changingthe position of the magnets relative to the desired region (containinginduction members/rotors, etc.), the positioning of the magnets relativeto one another, can change the field and hence the flux (FIG. 4). Forexample, magnets M_4_100 and M_4_110 are further away in FIG. 4( b) thanin FIG. 4( a), reducing the field in the induction/hysteresis memberI_4_200.

3. One or more magnets with Flux Return Path: Here, additionally to 1and 2 above, any means of changing the effective reluctance of any fluxreturn path will cause modulation of the field. FIG. 5 illustrates thisfor the case of two magnets M_5_100 and M_5_110, with flux return pathsusing ferromagnetic material (back-iron BI_5_400). Flux can be changedby moving two magnets further away, increasing air-gap Ag1_5_300 (FIG.5( a)), or keeping the magnets stationary, but changing the size of anauxiliary air-gap Ag2_5_310 in the magnetic circuit by moving aferromagnetic insert P_5_310 (FIG. 5( b)), or any similar means, wherethe flux path reluctance is changed by mechanical motion of one or moreof its constituents.

In all that follows, for simplicity, we shall often depict a singlemagnet inducing currents/force in an induction member. It should beunderstood that the single magnet can be replaced by any of theassemblies described above and similar variants.

[2] Control of Induced Force/Current by Changing Induction/HysteresisMember & Magnet Properties

The induced current, and hence induced force, is dependent both on theflux and on the geometry of the induction member, its dimensions(length, width, thickness), and its effective conductivity. Theeffective conductivity depends on the material, its texture, e.g.,whether it is solid, slotted, perforated, etc. Changing any of theseparameters changes the induced current, and hence the inducedforce/torque. The induction members may be merged with other materialsto achieve properties other than conductivity. Exemplarily, they couldbe part of multi-layer assemblies, satisfying desired mechanicalstrength properties in addition to conductivity etc. Alternatively, theycould be coated for corrosion resistance, etc. We additionally note thatthe same applies to the magnets, whose geometry, dimensions, material,number, etc., can be analogously chosen to suit.

[3] Dynamically Controlling Force by Changing Flux and Induction MemberProperties During Operation of Apparatus

This pertains to the use of our techniques to control non-uniform motionin apparatus incorporating general mechanisms. Flux changes can be madein a dynamic manner as a part of the regular operation of the apparatus.Exemplarily, the flux path can be made to periodically change reluctanceby the techniques outlined above. Additionally, the use of ferromagnetichysteresis members automatically results in change in flux pathreluctance whenever there (see Section A[4] and FIG. 6 below) isrelative motion of one or more hysteresis members in the magnetic field.This flux path change can be automatically driven by the operation ofthe apparatus itself. Flux changes can also be made by dynamicallychanging the shape of the magnets themselves.

Even for a given fixed flux, the strength of the induced current, andhence the induced force/torque, can be modulated by:

1. Changing the induction member thickness, with maximum thickness atthose positions where maximum force is desired. In positions where zeroforce is desired, the thickness can be zero, e.g., the conductivematerial is cut out at those positions.

2. Using higher conductivity material at positions where more inductiveforce is desired (e.g., a copper sector in an aluminum disk, etc.).

3. Using an induction member with varying degrees of material thickness,slottedness, perforatedness, etc., or any means that effectivelymodulates conductivity.

4. Using induction members of different geometry, e.g., induction drumsand members of other geometry well-known in the state-of-art. Theinduction member geometry can change in different positions, e.g., adisk having a raised cylindrical flange, which occupies only part of thedisk circumference.

5. Using multiple induction members, possibly of different geometry,dimensions, and material properties with one or more magnets.

All these modifications to the inductive strength can either be madeduring the manufacture of the apparatus or customizable at the time ofuse of the apparatus, e.g., by slots being provided for attachingmodifications to induction members, magnets, etc. (FIG. 24).

[4] Differences Between Force/Torque Control Using Induction and UsingHysteresis

Hysteresis effects can be used instead of induction effects to generatecontrollable force/torque. Hysteresis members of various materials,sizes, shapes, etc., can be designed to apply a desired force/torque,analogous to the design of the induction members above. The majordifference is that hysteresis forces/torques are independent (to a firstapproximation) of speed, while induction forces/torques are proportionalto speed (at speeds where the skin effect is not significant). Inductionmembers provide automatic self-limiting by increasing force/torque asspeed increases, and can also be used without stick-slip at very lowspeeds. If hysteresis members are used, then the forces/torques areconstant with speed. Control of force/torque using fixed hysteresismembers can be achieved by changing the flux, thus changing the strengthof the hysteresis effect, or by changing the radial position of thehysteresis effect, thus increasing torque while the force is keptconstant.

Hysteresis and induction members can be used in conjunction with eachother, to provide force characteristics having a fixed force componentindependent of speed, and a variable component linearly proportional tospeed. Separate induction and hysteresis members, or members having acombination of hysteresis and induction material, can be used for thispurpose (for example, copper inserts in a steel disc, or use of acopper-iron alloy possibly made using power metallurgy). The forceproduction may be changed as desired with time, exemplarily alternatinginduction, hysteresis, etc. For example, in FIG. 6, the mixedinduction/hysteresis disk I_6_200 is rotating about axle A_6_300 in theproximity of stationary magnet M_6_100. The aforesaid mixedinduction/hysteresis disk has four steel hysteresis inserts (one isH_6_210) in a copper induction disk, and can be used for sophisticatedtiming control. One important feature of hysteresis members, shared withmagnetic members, when the motion is non-uniform, is that hysteresismembers, being ferromagnetic, are attracted to the magnets. Thisintroduces rest positions (low-energy stable states) for the apparatus,which can provide latching behavior (monostable, bistable, etc.).Typical induction members made of copper/aluminum do not introducepreferred rest positions. The use of nonlinear unidirectional elementslike diodes offers nonlinear force vs., speed behavior, with breakpointsbeing settable in either direction, as described above (FIG. 2( d)).

[5] Issues When Both Interacting Members Have Independently ProducedMagnetic Fields

This issue arises when magnets are used both to generate the flux, aswell as to interact with the flux to modulate motion (e.g., a magnet onthe moving induction/hysteresis member itself). Such autonomouslymagnetic interacting members introduce one major new issue, in that now,because of the presence of both magnets, there may be preferred restpositions (energy minima) for the apparatus, keeping like poles as farapart as possible, and unlike poles as near as possible. Mechanicalmonostables, bistables, and astables can be thus designed and cascadedto perform mechanical logic. Design using such devices can be carriedout by techniques similar to induction/hysteresis members, together withwell known electromagnetic field interaction equations, using possiblyprinciples of virtual work.

Induction forces, hysteresis forces, and forces produced usingautonomously magnetic interacting members can be used solely or in anycombination. An example would be a modification of the mixedinduction/hysteresis disk in FIG. 6, to replace two out of four steelhysteresis inserts by magnets, with like/unlike poles facing thestationary magnet M_6_100.

[6] Reduction of Random Disturbances to the Induced Force/Torque

The force/torque exerted on the apparatus depends on the relativeposition of the induction/hysteresis member, and the magnet or magnetsgenerating the flux (in addition to other factors like geometry, size,speed). Random disturbances encountered during motion can cause therelative position of the induction/hysteresis member and magnet/magnetsto change, causing the force/torque to vary randomly and disturbing theresulting motion. Various mechanical means of minimizing the randomdisturbances are known, including damping, constraining the relativemotion of the magnet or magnets, and induction members, using bearings,etc.

A preferred low-cost embodiment of these ideas in our invention,applicable when the induction member moves and the magnet is stationary,is the structure shown in FIG. 7 (showing the Load Control structure ofFIG. 14, below). FIG. 7 shows a single magnet M_7_100 near an inductionmember R_7_200, applying induction torque to the induction member,rotating on axle A_7_310. In addition, the structure holding the magnetis further extended towards the inside of the induction member, to forma low-friction contacting bearing for the induction member (disk in thiscase). The bearing ensures that disk axial vibrations are minimized,resulting in a substantially constant position of the induction memberwith respect to the magnet M. This helps keep the induction forces andhence speed constant (note that the bearing is low-friction). Changingthe speed can be achieved by either radially or axially moving theentire assembly, using apparatus not shown (as shown later in Section Don Load Control).

The technique can be used when both the induction member and the magnetsmove (e.g., the induction gear of FIG. 11). The contacting bearing isattached to any stationary portion of the mechanism and provides supportfor the moving members at or near their interaction region. For theinduction gear of FIG. 11, this is shown in FIG. 12.

This method of providing bearing support for the induction/hysteresismember or members and/or magnet or magnets, at or near their interactionregion, can be extended in many ways, with different kinds of bearingstructures, possibly involving balls and/or rollers also.

B. Power Control: Physically Changing Motor Geometry/Dimensions

The speed of a motor is changeable by changing the intensity of thefield interacting with the rotor (field-weakening speeds up the motor atlow torque and slows it down at high torque). Classical techniquesexploiting this behavior typically deal with wound field coils, whosecurrent can be controlled to generate the desired field. Unfortunately,these methods are not applicable for very-low-cost apparatus operatingoff one or two batteries, as they assume some kind of powered controlcircuitry, together with power MOSFETS. Even for general apparatus, theability to avoid electronic control is intrinsically useful.

This invention can achieve the control of motor-delivered power, byvarying the physical geometry of the motor flux path, resulting in oneor more of the following:

1. Change in the field strength, by increasing the reluctance of theflux path. The stator pole pieces P_8_300 and P_8_310 are moved furtherapart in FIG. 8( b) compared to FIG. 8( a), weakening the field.Field-weakening can also be accomplished by applying any of the variantmethods in Section A (e.g., changing the auxiliary air-gap Ag2_5_310 inFIG. 5).

2. Change in the position of the field relative to the rotor. In FIG.9(b), the rotor R_9_300 is partially outside the field area, compared toFIG. 9( a), lessening the interaction between the field and the rotor.The required motion of R_9_300 is done by mechanical means well known inthe state-of-art.

3. In general, a change in the “effective” strength of the interactionof the field and the rotor.

The motor-delivered power can be changed within a single cycle by makingthe flux and rotor geometry deliberately asymmetric. For example, thestator-rotor air-gap can be modulated within a single cycle by using arotor that is an elliptical cylinder. In principle, any desiredvariation of torque with rotor angular position can be generated. FIG.10 shows such a modified motor, with windings omitted for clarity, butassumed to be on the rotor (both the rotor and the stator are assumed tobe ferromagnetic as per the state-of-art). The torque changes within asingle cycle, which is useful for timing control. In FIG. 10( a), ahigh-torque configuration is shown, with the rotor R_10_300 aligned withits long ellipse axis parallel to the field generated by the pole piecesP_10_310, resulting in a low effective air-gap and high magnetic field.In FIG. 10( b), the torque is low, due to the rotor R_10_300 beingaligned perpendicular to the field, resulting in a high air-gap and lowfield. In FIG. 10( c), the rotor R_10_320 is made cylindrical ofnon-ferromagnetic material, but has ferromagnetic inserts at rightangles to the flux path, to offer a flux path similar to FIG. 10( b). InFIG. 10( d), a similar cylindrical non-ferromagnetic rotor with insertsR_10_330 is used, but with dissimilar pole pieces P_10_310 and P_10_320.This creates an asymmetric magnetic field and allows even more controlof speed/torque. Torque/speed is high only when the ferromagnetic insertis close to the larger pole piece. Torque/speed is intermediate when theferromagnetic insert is close to the smaller pole piece, and smallestwhen the inserts are perpendicular to the flux path. The positioning ofthese inserts can be made at the time of usage of the invention,enabling customizability of the torque with respect to angular position(similar to that depicted in the Load Control of FIG. 24). Additionally,mechanical counterweights, etc., can be provided to minimize thevibrations due to the asymmetric structures involved. The method clearlygeneralizes to electromagnetic actuators used in general mechanisms withnon-cylindrical geometries (see Section E).

All this enables sophisticated variation of torque with respect toangular position and time, at far lower cost compared tomicroprocessors, sensors, and servos. The design of the magnetic circuitcan be made based on well-known electromagnetic and electrodynamiccomputational methods, which can estimate flux/force/torque for acomplex geometry, at certain angular positions, using possiblyfinite-element and/or boundary-element methods.

This issue is explored in greater detail in timing control using LoadControl (Section D, which uses the methods of Section A, especially seeFIGS. 20-24), as well as in Section E on general mechanisms.

C. Power Transmission Control

Electromagnetic force transmission is utilized in eddy-current andhysteresis clutches, well known in the state-of-art. It is also wellknown (see Section A) that the transmission of force usinginduction/hysteresis is dependent on the geometry, dimensions, “texture”(solidity/slottedness/perforatedness), and material properties of theflux-generating and induction/hysteresis members. Exploitation of thisproperty enables us to control the transmission of force/torque betweena driving and a driven apparatus, in any desirable fashion. This isillustrated by the example of a gear train, using induction force, whose“effective gear ratio” can be changed, but whose resultant speed-torquecharacteristics are not necessarily in inverse proportion.

In FIG. 11 (an axial cross-section view), a driving axle DGA_11_310 hasone or more magnets M_11_100 (as per Section A) inducing force on aninduction disk IM_11_200, on a driven axle DNA_11_320. Details of themagnets and their design are described below in the section on LoadControl. Unlike mechanical gears, force is induced only if there is a“slip” between the driven axle and driving axle. The thickness (or otherproperty modulating inductive force) of induction disk IM_11_200 is moreat the center. Hence, as the magnets approach the center of the drivenaxle, the transmitted force increases and can be arranged to cancel outthe reduction in lever arm partially, fully, or even more. Hence,modulating the thickness enables any desired speed-torque profile to beachieved, as “gear-ratio” is changed. In a variant, the two axes can beperpendicular (see FIG. 13). In another variant (FIG. 12), a contactingbearing, attached to driven axle DNA_12_320, minimizes the effect on theforce/torque of random vibrations of the disk DM_12_300, as per thediscussion in Section A.

This yields a new apparatus, a continuously adjustable electromagneticgear train whose speed-torque transmission characteristic can bedesigned to suit, by modulating induction-member properties (the“effective conductivity” as per Section A), and derived new apparatuscomprised of multiple electromagnetic gears forming a chain, whosespeed-torque characteristics can be similarly designed to suit.

The transmitted torque can be made to vary in a single rotation cycle ofeither the driving axle DGA or driven axle DNA, by making theinduction-member properties change as a function of angular position.Slower, possibly aperiodic variations of torque can be made usingauxiliary mechanisms changing the flux, the position of the appliedforce relative to the axis, etc. (see the discussion of theelectromagnetic CAM in FIG. 47( c). This issue is discussed in PowerControl (FIG. 10) and in Load Control (Section D, which uses the methodsof Section A).

FIG. 13 shows a variant, where the force transmitted is due to magneticrepulsion between like poles (N). Here, the driving axle DGA_13_310 isperpendicular to the driven axle DNA_13_320. DGA_13_310 rotates a set ofmagnets M_13_100 on disk DM_13_300, whose north poles face in the sameangular direction (FIG. 13( b)), and whose south poles are enclosed byback-iron BI_13_400 as shown in FIG. 13( b). Similar magnets M_13_110_(—) a and M_13_110 _(—) b (larger) and back iron are mounted in amanner to have north poles facing the magnets M_13_100, on a diskDM1_13_330 on driven axle DNA_13_320. Magnet M_13_110 _(—) b is largerthan magnet M_13_110 _(—) a. As DGA_13_310 rotates counter-clockwise(FIG. 13( b)), the repulsive force between magnets M_13_100 and M_13_110_(—) a causes DNA_13_320 to rotate. As “gear-ratio” is changed bybringing DM_13_300 inwards towards M_13_110 _(—) b, the maximumrepulsive force increases, because M_13_110 _(—) b is larger thanM_13_110 _(—) a. This increase can partly, completely, or more thancompletely cancel out the reduction in lever arm, as DM_13_300 isbrought inwards. Any given speed-torque profile can be configured byappropriately designing the sizes and shapes of all the magnets. Thedirection of rotation can be reversed by having unlike poles face eachother, thereby using magnetic attraction instead of repulsion. Forcetransmission is dissipationless in this variant.

This Power Transmission Control technique generalizes to generalmechanisms, in which case, the transmission of motive force or torquecan be made an arbitrary function of transmitted speed ratio, bysuitable design of the intermediate force/torque transmission mechanism.The required electromagnetic force is generated by suitable design ofthe induction/hysteresis members and/or magnets/other flux-generatingmembers. We note that such mechanisms have the property that theconnection between the different members is not rigid and canaccommodate unexpected disturbances, constraints outside its kinematicdesign, etc., in a fail-safe fashion.

D. Load Control (Powered and Unpowered Devices)

Load Control involves applying a controllable electromagneticforce/torque, possibly produced by magnetic attraction/magneticrepulsion/induction/hysteresis, to an apparatus, leading to change inapparatus speed/timing/force. The apparatus may be unpowered (e.g.,powered by means other than a motor/IC engine, such as human power) ormay have a prime mover.

In FIG. 14, we show an induction member shaped as a rotating conductingdisk R_14_200 with a magnet M_14_100 positioned, with possibly someair-gap (not shown) near it. This induction member is attached to theapparatus to be driven, which is external to FIG. 14 and not shown. Theapparatus is either unpowered or is rotated by a prime mover such as anelectric motor, which is external to FIG. 14. As described in Section A,the magnet M_14_100 may be replaced by an arbitrary magnet assembly.M_14_100 may be used singly or in combination with a plurality ofsimilar or dissimilar magnets, on just one side of the disk or on bothsides, with flux possibly being connected by back-iron. When more thanone magnet is used, the poles can be opposed to each other (north facingnorth) or complementary (north facing south).

The position of magnet or magnets M_14_100 with respect to the axis Acan be varied, using some mechanism external to FIG. 14, with FIG. 14(a) being the closest and FIG. 14( d) being the farthest. By principle ofmagnetic induction, the induced eddy-currents are least in FIG. 14( a),since the relative velocity of the magnet with respect to the inductionmember is the smallest. As such, the induced forces are smallest in FIG.14( a). The torque is relatively even smaller, due to the small distanceof the small force from the axis. This leads to a high rotation speed.The magnet M_14_100 (or other flux-generating device) is successivelymoved radially outwards in FIGS. 14( b) and (c). This causes increasedvelocity between the magnet M_14_100 (or other flux-generating device)and the induction member, increased eddy-currents, and hence increasedtorque, resisting motion. This causes the apparatus to operate slower inFIG. 14( b), and slowest in FIG. 14( c). In FIG. 14( d), the magnet ispartially outside the induction member, causing the apparatus to speedup due to reduced overlap of the field and the induction member. Hence,speed control is achieved by adding a controlled amount ofinductive/hysteresis load, while the prime mover is possibly (but notnecessarily) continuously producing a constant amount of torque. Themotion is smooth, since at low speed the high-inductive load dominatesany stick-slip that may be present, while stick-slip reduces, andinertial forces increase, at higher speeds. Based on the methods of fluxcontrol discussed in Section A, alternative embodiments of the inventionare available, and some are described below.

FIG. 15 shows speed control by moving the position of the magnet ormagnets M_15_100 axially away from the induction member R_15_200,reducing the flux, while maintaining the same radial position. This hasthe advantage that the distribution of eddy-current in the inductionmember R_15_200 is roughly invariant from FIG. 15( a), FIG. 15( b), andFIG. 15( c), potentially improving control linearity.

FIG. 16 shows a magnet assembly, with one or two magnets being used,together with ferromagnetic flux return paths, to form a partiallyclosed magnetic circuit. The position of the assembly relative to theaxis of the induction member can be varied, and/or the flux return-pathreluctance can be varied by varying an auxiliary air-gap in the fluxreturn path. This is further illustrated in FIG. 17, where an air-gapAg2_17_300 is shown in the middle of the flux return path, whosedimensions can be altered by moving ferromagnetic insert P_17_310 asshown. The magnet(s) M_17_100 and M_17_110 can be on the faces of theflux return paths as in FIG. 17( a) or somewhere else in the flux pathas in FIG. 17( b).

Many alternative geometries for the induction member are possible, e.g.,an induction drum as shown in FIG. 18. Here, the magnets are positionedsuch that the field crosses the induction drum. Inductive force andhence torque can be varied by varying the air-gap, the overlap of themagnetic field with the induction drum, or similar means, exactlyanalogous to the description for the induction disk above.

In the exemplary illustrations, we have shown magnets at one position ofthe induction member. This creates an unbalanced force in general, whichcan cause the apparatus to move/shake, etc. This unbalance can beeliminated by placing several magnets, e.g., symmetrically at equalangular positions from each other, producing a zero net force, butnonzero torque.

In all these cases, the induction force depends on the relative positionof the induction disk and the magnet or magnets used. As described inSection A[6], a contacting bearing (FIG. 7) can be used to reduce theimpact of random disturbances, where the configuration of FIG. 15 isshown. This method can also be used with the configuration of FIG. 17,with an auxiliary air-gap Ag2_19_300 and similar modifications (FIG.19). If, in the configuration in FIG. 19, the two magnets M_19_100 andM_19_110 have complementary poles facing each other (north of one magnetfacing south of another), then the flux is roughly constant in the gapbetween the magnets. This reduces but does not eliminate the impact ofaxial vibrations on the induced force/torque. If the poles are opposed,however, then the flux impinging on the induction disk is greatlydependent on the position, and the contacting bearing helps keep thisconstant with respect to vibrations.

Our techniques work for induction members and magnets of any geometrythat has an overlap of the magnetic field with the induction member.While the discussion has been in terms of fixed magnets and movinginduction members, the invention applies equally to moving magnets andfixed induction members, and similarly to cases where both move. Theinvention applies equally to the use of hysteresis members and to theuse of multiple, autonomously magnetic interacting members (with themodifications outlined in Section A[4], A[5]), either singly or inconjunction with the other techniques.

[1] Load Control: Embodiments Performing Timing Control by ChangingSpeed in One Cycle

The discussion so far has centered on controlling uniform motion ofrotating apparatus, by controlling the relative position of one or moremagnets (permanent or electromagnets) and/or one or moreinduction/hysteresis members. This section extends the scope of theinvention to control non-uniform motion, allowing sophisticated timingto be generated, at far lower cost compared to microprocessor-controlledservos. In all the discussion, the same apparatus referred to in FIGS.14 through 19 is considered, but with modified means of motion control.

In FIG. 20, a disk R_20_200 with one sector which has been cutout isused as the induction member. Henceforth, we shall use the term “cutout”to both denote the action of removing material, as well as the portionof the disk where material has been removed. A nonconductive materialmay or may not be added in the cutout portion, based on a variety ofconsiderations (not shown). As such, the inductive force/torque producedis now angular-position-dependent and is maximum when the magnetM_20_100 (or magnets M_20_100 in any of the configurations as perSection A) is over the conducting/non-cutout sectors of the inductionmember (FIG. 20 (a)). This inductive force/torque is lower when themagnet is at the periphery of the induction member cutout sector (FIG.20( b)), and close-to-zero when the magnet M is over thecutout/nonconductive portion (FIG. 20( c)). This varies the speed withina single rotation, with maximum speed with the magnet over the cutoutportion and minimum speed with the magnet over the conducting portion,allowing sophisticated timing control. Note that this control can beused singly or in conjunction with moving the radial position of themagnet, changing the air-gap, etc., as outlined previously (Section D).When used in such a manner, the speed variation has a componentcorresponding to variation within each cycle due to the cutout and ageneral possibly aperiodic variation due to the other control exerted(see the discussion of the CAM in FIG. 47).

Multiple cutouts can also be used, resulting in multiple locations ofhigh speed, as shown in FIG. 21, where three cutouts are shown.

As discussed in Section A, the structures illustrated in FIG. 20 andFIG. 21 have a magnet assembly only in one position, possibly generatinga net shaking force to the apparatus. The net force can be eliminated byusing symmetric induction members and multiple magnet assemblies equallyangularly spaced. If K equally angularly spaced magnet assemblies areused, the cutout structure determining the timing is replicated K-timesover the circumference of the disk. For example, FIG. 22 shows asymmetric version, R_22_200 of FIG. 21 with six cutouts instead ofthree, each half as big in angular extent as those of FIG. 21, alongwith two magnets spaced half a revolution apart, M_22_100 and M_22_110.We can repeatedly slot/perforate the disk to partially but notcompletely lower the induction force/torque, as shown in theslotted/perforated area SPA_23_300 in FIG. 23. As long as the slot/holepitch is small, the high-order harmonics of the force/torque arefiltered out by the inertia of the apparatus, allowing us to vary theinduction force/torque in a continuous fashion, exactly analogous topulse-width modulation systems.

In general, all the methods of controlling force/torque in Section A canbe used. These include:

1. Changing the induction member (disk) thickness, with maximumthickness at those positions where more force (minimum speed) isdesired.

2. Using higher-conductivity material at positions where more inductiveforce is desired (e.g., a copper sector in an aluminum disk, etc.).

3. Using an induction member with varying degrees of material thickness,slottedness, perforatedness, etc., or any means that effectivelymodulate conductivity.

4. Using induction members of different geometry, e.g., induction drums,and members of other geometry well known in the state-of-art. Theinduction-member geometry can change in different positions, e.g., adisk having a raised cylindrical flange, which occupies only part of thedisk circumference.

5. The same applied to the magnets, whose geometry, dimensions,material, number, etc., can be analogously chosen to suit and can bedynamically varied during an operation cycle. For example, the disk withcutouts R_23_200 in FIG. 23 can be a (large) magnet, and the magnetM_23_100 becomes a small induction disk instead.

6. Dynamically changing the magnetic field by changing the field path inany manner, including changing the flux return path, the distance ofmagnet (or magnets) from induction disk, etc.

7. Dynamically changing the shape of the magnets themselves toselectively engage induction members.

8. Using multiple magnets and induction members, possibly of differentgeometry, dimensions, and material properties, e.g., conductivity. Forexample, two disks can be used with a magnet for each (possibly atdifferent positions). The resultant force/torque is the sum of theindividual force/torques, and offers additional flexibility in thetiming/force profile.

9. The air-gap between the magnets and the induction/hysteresis disk canbe changed to change speed at all positions simultaneously (fluxcontrol, Section A).

10. All of the above using induction effects, hysteresis effects, and/ormultiple autonomously magnetic interacting members, solely or incombination. In the case of the last two, the emergence of preferredrest positions of the apparatus enables the apparatus to offerfunctionality not previously present (Section A[4], and A[5]).

The functionality of timing control is present in all these variants,and these variants are therefore within the scope of this invention.While the description discusses one or a few variants, extension of theinvention to include all the variants is implied. Additionally, theresultant timed motion can be put to several uses, for example, playingmusical tones, passive anti-lock braking systems (due to the pulsatingforces induced in a slotted induction member), etc. The scope of theinvention includes all such variants.

The period of rotation or reciprocation of an interaction(induction/hysteresis) member may be different from the period of motionof the apparatus, with auxiliary mechanism being used to initiatechanges in electromagnetic interaction intensity based on the currentposition of the apparatus in its period. An example is a turntabledriven by an electric motor through a gearing mechanism. The currentposition of the turntable platform can (through an auxiliary mechanism)change the position of a magnet relative to an induction member mountedon the motor shaft. This changes the induction/hysteresis/magneticforces with a relatively long period, while retaining the highforces/torques due to the high speed of the motor shaft.

[2] Load Control: Embodiments where Timing Can be Changed During Use

The invention can be further enhanced to provide user customizability bymaking the induction member properties changeable at time of use. Theseproperties include but are not limited to changing the geometry of thedevice, its effective dimensions, effective conductivity, magneticreluctance path, etc. In all the discussion, the same apparatus referredto in FIGS. 14-23 is considered, but with modified means of motioncontrol.

One embodiment of this invention is shown in FIG. 24. Instead of a soliddisk, we show a frame FR_24_310 with slots SL_24_300 for inductionmembers IM_24_200, IM_24 _210 of various types. Magnets M_24_100 andM_24_110 (or a general assembly M_24_100, as discussed in Sections A andD) are positioned above and below the frame FR_24_310. The magnetsM_24_100 and M_24_110 can be in other suitable positions so as to createa magnetic field interacting with the frame FR_24_310. The design of theslots can be of various types well known in the state-of-art, and theslots can be fully enclosing, partially enclosing, or any other kind ofattachment. The slots can also be nonconducting, partially conducting,or fully conducting themselves. At the time of usage of the apparatus,the user can selectively insert induction members of various types asdiscussed in Section A. This introduces user programmability into thetiming control, with lower speed at the places where the inductionmembers are inserted and higher speed where they are not This extensionof the invention admits of the following variants:

1. Each type of induction member IM_24_200/IM_24_210 attached to a slotin the frame applies a certain force/torque to the rotating inductiondisk, when the magnet/magnets M_24_100/M_24_110 is positioned over it,resulting in a specific speed. The number of these slots, frames, andattached induction members IM_24_200/IM_24_210 can be varied, all theway from a single (small or large) frame with one slot for an insertableinduction member, to multiple frames, each with multiple slots forinduction members. The sizes and thickness of the slots andcorresponding induction members IM can be varied. Multiple inductionmembers can be inserted into one slot, for even more control. Ingeneral, all the variants of induction members described in Section Acan be used.

2. Instead of a frame shaped like a disk, a frame shaped as an inductiondrum (or other geometry) can be used, following the discussion in FIG.18, with an appropriate arrangement of slots for inserting inductionmembers.

3. Instead of an induction disk/drum, a hysteresis disk/drum can beused. In general, any user-changeable geometric structure (e.g., a conewhose angle can be varied) with overlap between magnetic fields producedby one or more magnets and/or one or more induction/hysteresis members,causing electromagnetic force/torque, can be used (refer the discussionin Sections A, A[4], and A[5]).

In closing, we mention two preferred embodiments of motors, where PowerControl, Power Transmission Control, and Load Control are used together:

1. An induction/hysteresis member, together with magnet M (magnets M)for Power Transmission Control and/or Load Control can be separatelyattached to the motor axle.

2. The induction/hysteresis member together with magnet M (magnets M) ofPower Transmission Control and/or Load Control can be co-located withthe rotor windings/rotor magnets of the motor, and both the poweringfield and the inductive/hysteresis forces varied together.

E. Embodiments of the Invention Forming General Mechanisms Able toControl Linear, Angular, and/or Possibly Multi-Degree of Freedom Motion

Power Control, Power Transmission Control, and Load Control can begeneralized to general mechanisms, such as 4-bar, Geneva, etc. possiblyincluding angular displacements, multiple degrees of freedom, e.g.,3-axis translation+3-axis rotation, etc. Our definition of a generalmechanism includes apparatus whose parts may be partly or completelyunconstrained (e.g., the carom board of FIG. 58) with respect to eachother.

(a) Power Control: This refers to control at the source of the power. Inmotors, the magnetic flux path geometry or properties of theinduction/hysteresis interaction members are physically changed,achieving modulation of the magnetic field and/or inducted currentsand/or forces/torques inside the machine. In general mechanisms,additionally, multiple powering sources (rotary or linear motors) arepresent, which are controlled in a co-operative manner to achievedesired motion. The state-of-art in field control, typically changes thecurrent exciting a field coil. The state-of-art of modulation ofpermanent-magnet field has not been applied to a low-cost electric motorfor controlling speed. One key idea here is varying the designparameters of the machine to achieve motion control, and can be appliedto all kinds of prime movers. For example, an IC petrol engine can becontrolled by varying the length of the stroke, using an appropriatemechanism.

(b) Power Transmission Control: This refers to control in the powertransmission chain. In rotating systems, the electromagnetic forcetransmission is controlled by varying the magnetic flux path and/orinduction/hysteresis member geometry, and is a generalization ofelectromagnetic clutches. In general mechanisms, additionally,force/torque can be transmitted through multiple portions of themechanism, and the mechanism is designed to make these multipletransmitted force/torques to be complementary.

(c) Load Control: The force produced by the interaction between one ormore magnets and/or induction members and/or hysteresis members ofsuitable properties (Section A) can be exerted at various states(positions) in the mechanism, using possibly multiple magnets and/ormultiple induction/hysteresis mechanism of suitable properties (SectionA) and suitably located. This will lead to the mechanism load and hencespeed being modulated at these selected states, allowing arbitrarytiming to be generated, even with the application of a constant drivingforce or torque (for simplicity, this is not necessary) to the wholemechanism. Note that the interaction between two magnets is adissipationless force. Energy is stored in the magnetic field inunstable states of the mechanism and returned when the mechanism movesto stable rest states.

The combination of power control, power transmission control, and loadcontrol enables new methods of designing mechanisms to satisfy desiredpath, timing, and loading characteristics. The design of the mechanismcan be based on kinematic principles primarily, with the mechanism paths(for the constrained portions) being used to develop the constraintsurfaces. (Dynamic issues like force/moment balancing have also to beaddressed, but can be substantially decoupled from the timing of themechanism, simplifying design.) Timing along the mechanism paths, aswell as force exerted by the mechanism on the prime mover or to theexternal environment in general, can be changed as desired at low costusing magnetic and/or inductive/hysteresis force/torque applied and/orcoupled at various positions, possibly in a programmable fashion. Whenmultiple magnets are used to generate force/torque, the presence of reststates enables energy storage at arbitrary states of the mechanism andenergy return at other states in a dissipationless manner to controltiming. Energy from external prime movers can be stored at those statesof the mechanism wherein the force/torque is best absorbed by themechanism. These states can be determined from design of the mechanism,e.g., based on the position function p(x(t)) described below, etc.Stored energy is used to continue to drive the mechanism at stateswherein the force/torque is either not generated from the prime mover ornot absorbed by the mechanism (e.g., see the internal combustion engineof FIG. 36). The use of induction/hysteresis members enables dampingforces with a customizable velocity-force profile to be applied asdesired.

In general, let x(t) represent the desired time trajectory (withmultiple components representing all possible linear and angular degreesof freedom) of an arbitrary point on some link/part (member) of themechanism. For example, in a reciprocating mechanism, x(t) can be apoint on a reciprocating shaft RS of mass M. Newton's law applied to themember (RS) results in Equation (1) as follows:x″(t)=f(x(t))/M,  (1)where f(x(t)) is the net force exerted on the member by the prime mover(we initially assume a single prime mover for simplicity) through otherportions of the mechanism and the electromagnetic load (possibly due tomagnetic attraction/repulsion and/or induction or hysteresis) atposition x(t). In the case of rotation, we have torque instead of forceand moment of inertia instead of mass in the above equations.

We reiterate that f(x(t)), the net force (or torque for rotationalmembers) on the member exerted through the mechanism, depends on theposition function p(x(t)) and the presence of force elements includingmasses acting under gravitational forces, springs, electromagneticforces due to magnets, hysteresis/induction loads, etc. These forces canthemselves be multiplied by ratios of lever arms and/or gears present inthe mechanism. The forces can also be modulated by the angle of contactof various constraint surfaces (which generate reaction forces to imposethe constraints), etc.

Let us assume that Power Control, Power Transmission Control, and LoadControl are all present. If, using Power Control, fp(x(t)) is the forcegenerated by the prime mover, f t((x(t)) is the percentage of forcetransmitted through the mechanism using Power Transmission Control,including any magnetic/induction/hysteresis coupling present, andfl(x(t)) is the force due to Load Control, including any frictionallosses and electromagnetic load (possibly magnetic, induction, and/orhysteresis), we get Equation (2) as follows:f(x(t))=fp(x(t))*ft(x(t))−fl(x(t))=Mx″(t).  (2)Note that, with the use of hysteresis and/or autonomously magneticmembers, fl(x(t)) can be negative due to energy stored in the mechanismin state x(t)—see the discussion on rest states below. For a desiredtime trajectory x(t), we can find f p(x(t)), f t(x(t)), and f l(x(t)) tosatisfy Equation (2), provided certain regularity conditions like energyconservation are satisfied. There are clearly multiple ways this can bedone.

-   -   (a) Load Control Only: Here f p(x(t)) and f t(x(t)) are constant        or not controllable for unpowered devices. Then, the amount of        force required to be exerted due to Load Control is given by        Equation (3) as follows:        fl(x(t))=fp(x(t))*ft(x(t))−Mx″(t)−ff(x(t))≅fp(x(t)*ft(x(t))−Mx″(t),  (3)        where ff(x(t)) is the frictional force, assumed to be small due        to the use of bearings, etc. This force can be used to determine        induction/hysteresis member geometry and/or the strengths of the        magnets used, etc. One major advantage of Load Control is the        lack of any stick-slip at low speeds, since both the load and        force applied are much higher than the static/dynamic friction.        Control using inductive/hysteresis members (not that depending        on magnetic attraction/repulsion) is dissipative.    -   (b) Power Control Only: We have Equation (4) as follows:        fp(x(t))=Mx″(t)+fl(x(t)))/ft(x(t))  (4)        Appropriate power control can enhance mechanism energy        efficiency.    -   (c) Power Transmission Control Only: We have Equation (5) as        follows:        ft(x(t))=(Mx″(t)+fl(x(t)))/fp(x(t))  (5)        If the structures used to implement power transmission control        are similar to clutches, this has the advantage that maximum        force transmittable is limited, enhancing safety.    -   (d) Any two or all three taken together.

The presence of rest states with both multiple autonomously magneticinteracting members and hysteresis members is equivalent to energyminima being present. The presence of these energy minima (andcomplementary maxima) provides additional degrees of freedom for motioncontrol, by making available releasable stored energy or equivalentlynegative loads in the mechanism.

Once fp(x(t)), ft(x(t)), and fl(x(t)) have been determined,electromagnetic parameters of the Power Control, Power TransmissionControl, and Load Control apparatus can be determined using standardtechniques of electromagnetics and dynamics.

By suitably designing Power Control, Power Transmission Control, andLoad Control, any desired time trajectory can be designed. For example,if x(t) is oscillatory without control, then an appropriate combinationof controls can convert a purely sinusoidal x(t) to one having a largenumber of harmonics, which is very useful in many kinds of applications,e.g., vibration benches for stress-testing equipment.x(t)=A cos(ωt)=>x(t)=Σ[A _(i) cos(ωt)+B _(i) sin(ωt)].  (6)An appropriate choice of controls using magnetic and/orinduction/hysteresis force changing continuously with position, cangenerate a broad spectrum of motion, with a close-to-continuous spectrumX(ω)).x(t)=A cos(ωt)=>x(t)=∫X(ω)e ^(−jωt)) dω  (7)In both these cases, the controls can also be applied in reverse,converting motion/force/torque from a multi-frequency (possiblycontinuous spectrum) exciting source to a motion/force/torque having asingle frequency (possibly zero). This can be exemplarily applied tosmooth out fluctuations from prime movers, e.g., the pulsating gas forcefrom an internal combustion engine can be converted to aclose-to-constant external force, utilizing electromagneticattraction/repulsion and/or induction/hysteresis forces, and withoutnecessarily using a heavy flywheel, e.g., as in Equation (8) as follows:x(t)=Σ[A _(i) cos(ω_(i) t)+B _(i) sin(ω_(i) t)]=>x(t)=A cos(ωt)  (8)So far, the discussion has treated a single prime mover and a singleload. The generalization to multiple prime movers and multiple loads isstraightforward, as in Equation (9) as follows:f(x(t))=Σ_(i) fp _(i)(x(t))*fti(x(t))−fli(x(t)) =Mx″(t),  (9)where the i^(th) prime mover generates force fp_(i)(x(t)), which istransmitted at the rate of ft_(i)(x(t)) to the member of interest and anportion of the total load fl_(i)(x(t)) is “assigned” to this primemover. Note that other forces like inertia/gravitational forces due toother masses, springs, etc., are assumed to be incorporated in one ormore fp_(i)(x(t))'s, where details are omitted for simplicity. We onlynote that, at different positions, different prime movers can bepowered, for example, only those for which the force transmission ratiois high. This can help prevent excessive internal reaction forces in themechanism. See the Power Control discussion of the three-link mechanismof FIG. 30 for more details.

Rest states of the apparatus (if hysteresis and/or multiple autonomouslymagnetic interacting members are used) can be determined by (1)determining the electromagnetic energy as a function of mechanismposition and (2) finding the minima Dynamics between states can bedetermined by solving the mechanism dynamic equations, accounting forany electromagnetic forces present. To synthesize an apparatus havinggiven rest states, nonlinear optimization techniques can be used todetermine the positioning of hysteresis members and/or multipleautonomously magnetic interacting members (magnets).

The description below is quite general and covers many differentembodiments of the present invention. An embodiment of PC, PTC, and LCfor a general mechanism is described and is followed by several majorillustrative examples.

Motion Control of General Mechanisms: Structure of an Embodiment

From one point of view, our work can be regarded as generalizations ofboth electric machines and general mechanisms to yield a new class ofdevices hereafter called electrical mechanisms. We further elucidatethese ideas below.

Mechanisms are described in the state-of-art as composed of rigid linksand connections between them (joints or pairing elements—higher or lowerpairs). Mechanisms composed only of lower pairs are known as linkages(planar or spatial). The invention applies to mechanisms having lowerand/or higher pairs. All the forms of the invention—e.g., Power Control,Power Transmission Control, and Load Control—can be applied to generalmechanisms. We shall first describe enhancement of the mechanism'sconstituents in their unpowered state (Load Control), and then discussenhancements of traditional arrangements to Power Control and PowerTransmission Control.

Generalization of Load Control

The invention adds to rigid links, members either generating orinteracting with magnetic flux (magnets and/or induction members and/orhysteresis members as per Section A). These members may be fixed at timeof manufacture or can be removably attached at the time of usage of theapparatus, similar to the programmable timing control disc with slots ofFIG. 24. In certain preferred embodiments, the aforesaid members can bepositioned close to a joint J on a link 1 and interact with othermembers positioned close to the same joint J on another rigid link towhich link 1 is joined at joint J. In such cases, we use the terminologythat joint J has been enhanced by the addition of the aforesaid members.When the mechanism is assembled, the mutual interaction of the aforesaidmembers determines rest positions and dynamics. There can be multiplerest positions, yielding monostables, bistables, as well as multi-valuedmechanical logic. Such mechanisms can be cascaded together to form logicfunctions, analogous to electronics.

Enhancement of Rigid Links

The invention attaches magnets and/or induction members and/orhysteresis members as per Section A to some or all of the rigid links.FIG. 25 shows an exemplary embodiment for a rigid link R_25_300 withthree revolute joints, one of which is J_25_320. J_25_320 is attached toanother rigid link R_25_310. Link R_25_300 is enhanced with one magnetassembly M_25_100 in the middle, and on M_25_100's left (per FIG. 25) bya hysteresis member H_25_210 and on M_25_100's right by an inductionmember I_25_200. The electromagnetic interaction between rigid linksR_25_300 and similar but not necessarily identical link R_25_310 willpartly determine mechanism rest positions (statics) and dynamics.R_25_310 has a magnet assembly M_25_110, a hysteresis member assemblyH_25_230, and an induction member assembly I_25_220. Depending on theorientation of the poles of M_25_100 and M_25_110, R_25_300 and R_25_310will attract/repel each other, and speed of motion will be determined byaforesaid attractive/repulsive forces, together with theinductive/hysteresis forces generated on R_25_300 and R_25_310 by themagnet/magnets M_25_100/M_25_110. Note that the number per link, shapes,sizes, positions, and magnetic properties (strength, spatialdistribution of field, etc.) of the magnet assemblies andinduction/hysteresis members may differ from that shown in FIG. 25.

Enhancement of Joints (Pairs/Pins)

As mentioned above, in certain embodiments, the magnets/hysteresismembers/induction members on one link are close to those on another linkto which it is joined, in which case, we say that the joint is enhanced.The invention allows enhancement of some or all the standard joints usedin mechanisms with electromagnetic forces—due to attraction/repulsionand/or induction and/or hysteresis. Exemplary embodiments are shown foreach one of the joints below:

-   -   (1) Revolute Pair: A preferred embodiment makes the revolute        joint pins and their housing magnetic (FIG. 26). The air-gap        between the pin and the housing may or may not change as the pin        rotates relative to its housing during motion of the mechanism.        The magnets may be attached to circular disks attached to the        pin and the housing to obtain more torque due to the larger        radius. In general, one or more induction members, hysteresis        members, multiple autonomously magnetic interacting members,        magnet/induction/hysteresis members of different geometry, etc.,        can be attached to the pin and/or its housing as per Section A.

FIG. 26( a) shows a (hollow) pin P_26_300 connected to a first linklink1_26_310 (not shown), rotating in a housing PH_26_320 connected toanother link link2_26_330 (also not shown). Note that a ball/rollerbearing may be present between P_26_300 and PH_26_320. The pin P_26_300is magnetized as shown in FIG. 26( b) with two north and two southpoles, while the housing PH_26_320 has a single north and a single southpole as shown in FIG. 26( c). These poles need not be equally spaced inangle, may be of unequal strength, can generate a general magnetic fluxdistribution, and can be more in number than as shown. Thismagnetization may be realized by (1) attaching magnetic material to thepins themselves, (2) making the pin of hard magnetic material andmagnetizing it, or (3) other means well known in the art. Additionally,there may be (a) an auxiliary sleeve of nonmagnetic material enclosingpin P_26_300 to prevent it from sticking to the housing due to magneticattraction or (b) other means (e.g., the aforesaid bearing) ofpreventing excessively close physical contact between the magnets on pinP_26_300 and those on pin housing PH_26_320.

The operation of such an enhanced joint is described as follows. FIGS.27( a) and (b) show the pin and its housing in two stable states, wherethe north pole of the housing impinges on a south pole of the pin, andFIGS. 27( c) and (d) show two unstable states, where the north pole ofthe housing is close to a north pole of the pin. All these states areoffset by one-quarter revolution in this embodiment (in general, thestable/unstable states may be unequally spaced). Hence, in themechanism, link1_26_310 and link2_x_330 would tend to occupy thoserelative positions resulting in P_26_300 and PH_26 _320 occupying eitherthe positions of FIGS. 27( a) or (b). The exact positions occupied willtypically depend on other portions of the mechanism.

-   -   (2) Prismatic Pair: An exemplary prismatic pair (sliding joint)        with magnetic interaction between first link Link1_28_300 and        second link Link2_28_310 is shown in FIG. 28. A set of magnets        (or assemblies as per Section A) M_28_100 on Link1_28_300        interacts with another set of magnets M_28_110 on Link2_28_310,        creating electromagnetic maxima and minima (rest states). The        number of magnets/assemblies on M_28_100 and M_28_110 need not        be the same, and these assemblies need not be equally spaced,        any may occupy one or both sides of the sliding joint. All        energy maxima or rest states need not be equally spaced or have        the same energy.

Induction and/or hysteresis members can be added to this pair,modulating the dynamics between any two states. Reciprocating motion offrequency less than a bandwidth B depending on the strength of theinduction/hysteresis, will be transmitted between Link1_28_300 andLink2_28_310. B, the 3 dB bandwidth of motion transmission, can becalculated by well-known techniques of electromagnetics and dynamics. Anexemplary embodiment of these ideas is the Extendible Tether of FIG. 59.

Screw Pairs, Cylindrical Pairs, Spherical Pairs, Planar Pairs, HigherPairs

The invention similarly enhances these pairs with magnets and/orinduction and/or hysteresis members.

-   -   (a) Screw Pair: The exemplary screw mechanism in FIG. 29,        converting rotary motion into translational motion and vice        versa (in some cases), can exhibit (1) rest states, possibly        non-uniformly spaced, either in angle or linear position along        the screw and (2) arbitrary customizable dynamics between one        state and another through the use of one or more magnets and/or        induction and/or hysteresis members attached to either or both        of the screw or the nut follower. Specifically, the rest states        of nut N_29_310 are determined by the interaction of magnets        M_29_100, M_29_110 (attached to screw SH_29_300), and M_29_120,        M_29_130 (attached to nut N_29_310 by means not shown), and        dynamics between these states determined by a combination of the        aforesaid magnetic interaction and induction forces induced in        I_29_200 interacting with the above-mentioned magnets.    -   (b) Cylindrical Pair: This can be regarded as a combination of        revolute and prismatic pairs, with both translation and        rotational motion, and the same considerations apply.    -   (c) Spherical Pair: This is a generalization of revolute pairs        to three dimensions. Rest states can be arranged at arbitrary        azimuth and altitude angles, and dynamics between one state and        another can be controlled using one or more magnets and/or        induction and/or hysteresis members.    -   (d) Planar Pair: The carom board of FIG. 58 is an example of a        planar pair, where the striker and pieces (constituting the        first rigid link) can move only on the board surface        (constituting the second link). Enhancement of the board and/or        striker and/or pieces with magnets and/or induction and/or        hysteresis members as per Section A enables the customization of        apparatus rest positions and/or dynamics.    -   (e) Higher Pairs: In pairs that have point contact, poles can be        placed on or near a set of contacting points on the pairing        members. Induction/hysteresis members can be placed on other        positions of the pair, modulating dynamics. For example, the        pieces in billiards and snooker have a point contact between one        member and the board surface, and the enhancements similar to        those of the planar pair apply. In pairs with line contact,        poles can be placed on or near a set of contacting lines. For        example, the rollers in a roller bearing can be magnetized to        preferentially occupy certain positions relative to the two        shafts coupled.

In certain mechanisms constructed according to the invention, some orall of the links and/or joints can be thus enhanced. It is not necessarythat all joints or even all joints of a certain type be enhanced in thesame manner. The interaction of all the magnetic and/or hysteresisforces will determine the rest position of the apparatus. The sizes ofthese forces can be controlled by suitable design and magnetizations ofthe magnets, induction, and hysteresis members on the links and the twoconstituents of some or all joints (pin and its housing for a revolutejoint) as per Section A. Suitable design and orientation of suchmagnetized links and joints can be used to realize any desired restpositions of the mechanism. If there are K desired rest positions forthe apparatus, then the magnets in the pairs/joints will have O(K)poles.

In an exemplary design for a mechanism with one degree of freedom withonly revolute joints (pins and housings), only one pin is magnetizedwith K north-south pole pairs, the housing has a single N-S pair, andthe rest are non-magnetic. A simple algorithm to determine the polelocations is to place a N-S pair on the pin, aligned with the S-N fieldon the housing in each desired rest state. In general, the resulting N-Spairs may be close together, in which case, multiple pins can bemagnetized with each pin having rest positions at a subset of the reststates of the whole mechanism. The selection of these subsets can bemade in a manner as to optimize criteria such as maximizing holdingforce, positioning accuracy, etc. Exemplarily, to maximize positioningaccuracy of any point on a link of the mechanism, the pin most sensitiveto changes in the aforesaid point's position can exemplarily have a reststate corresponding to each desired location of the aforesaid point.Multiple pins/housings may be magnetized at the same desired locations,possibly yielding higher holding forces for bothsingle-degree-of-freedom mechanisms and multiple-degree-of-freedommechanism. The number of N-S pairs in each pin/housing may in generaldiffer. In general, the magnetic strengths of the N-S pairs can differ.

In general, dynamic motion between two states can be controlled by anyof the variants using possibly induction/hysteresis effects, multipleautonomously magnetic interacting members, induction/hysteresis membersof different geometry, etc. as per Section A. Exemplarily, these forcescan be used to slow down “ratcheting” between states, e.g., as in theejector/latch of in FIG. 50.

Connecting links and joints/pairs enhanced in the aforesaid manner asper the invention, enables creation of mechanisms of arbitrarycomplexity ranging from 4-bar linkages and its variants (includingquick-return mechanisms), Geneva Mechanisms, the Watt Chain, theStephenson Chain, and Chebychev's walking mechanism (exemplarily, herethe rest states can be designed to fold the legs in a crouchingposition), etc. An advantage of this invention is that the motionbetween the states is noiseless, unlike ratcheting alternatives wellknown in the state-of-art.

Generalization of Power Control

From one point of view, the invention is a generalization of well-knownstepper motors to create stepper mechanisms (especially if there arepowered coils in addition to permanent magnets on the pins). Changingthe coil excitation “steps” the mechanism through its different reststates, which can be chosen to be on an appropriate, possiblynon-uniform grid for one or more points in the mechanism.

FIG. 30 shows an exemplary three-link mechanism (this is actually a4-bar linkage with one infinite link) composed of rigid links R_30_300,R_30_310, R_30_320, with a revolute joint J_30_400 connecting R_30_300and R_30_310, another revolute joint connecting R_30_310 and R_30_320,and a prismatic joint J_30_410 connecting R_30_300 and R_30_320.Depending on (i) the relation between the lengths (between the joints)of R_30_300, R_30_310, and R_30_320, and (ii) the extent of travelallowed by joint J_30_410, the mechanism may or may not allow completerotation of R_30_310. Some or all joints are enhanced as per theinvention with magnets and/or hysteresis and/or induction members,possibly with varying shapes, sizes, materials, texture, etc. as perSection A. In addition, magnet M_30_100 and induction member I_30_200interact to produce an inductive braking force.

Powered coils PC_30_330 and PC_30_340, attached to R_30_300 (or R_30_310), cause motion at joint J_30_400. Powered coils PC_30_350 andPC_30_360, attached to R_30 _300 (or R_30_320), cause motion at jointJ_30_410. The coils can be on more than one link in general and areconstructed with ferromagnetic cores, as is well known in thestate-of-art. The flux produced by the aforesaid powered coils can varywith angular position of J_30_400 and linear position of J_30_410,similar to the discussion on motors with an ellipsoidal rotor (SectionB). An appropriate design of the joints (position, number, energy levelof the rest states, etc.), together with sequencing and control of theelectrical excitation to the aforesaid coils from control circuitryCP_30_500, will make the mechanism step between states, exactlyanalogous to stepper motors taking steps.

The invention distinguishes itself from the state-of-art in severalways.

-   -   (a) In FIG. 30, the set of links forms a closed loop, and the        amplitude and sequencing of the excitation to the different        joints has to be chosen to generally (but not always) to avoid        opposing each other. This is unlike kinematically chained        powered robotic arms, where the excitation to the different        actuators can be substantially independent, the only constraint        being the desired path of the kinematic chain.    -   (b) In addition, the set of powered coils PC_30_330, PC_30_340,        PC_30_350, PC _30_360 need not form the windings for one        complete rotary motor and one complete linear motor, but are        placed so as to optimize a desired criterion, e.g., power        delivery, fineness of control, etc. If power delivery is the        criterion, coils PC_30_350 and PC_30_360 are placed and        controlled so as to apply force in the middle of the travel of        prismatic joint J_30_410, since the mechanism cannot be moved by        a linear force, when rigid link R_30_310 is exactly in line with        R_30_320 and joint J_30_410 (this happens at extremities of        travel). Even if the mechanism does not allow R_30_310 to        perfectly align with R_30_320, the effectiveness of the linear        force is reduced at the extremities of travel of J_30_410.        Powered coils PC_30_330 and PC_30_340 are placed and controlled        to apply force at those positions of revolute joint J_30_400,        which positions correspond to the mechanism having prismatic        joint J_30_410 at its extremities, so as to compensate the lack        of drive from PC_30_350 and PC_30_360. They can be unpowered or        designed to not apply any force/torque at other states of        revolute joint J_30_400. This control can be driven by the        mechanism's motion itself, opening and/or closing switches,        generalizing the action of commutators in electric motors.        Essentially, the apparatus of FIG. 30 is a “hybrid rotary-linear        motor,” and all powered coils and flux paths have to be jointly        optimized.    -   (c) A variant of this apparatus uses another magnet M_30_110,        with its poles arranged so as to repel M_30_100 near its extreme        right (per FIG. 30) position. This provides a sideways force to        R_30_310 in the extreme right position, causing it to move.        Essentially energy is stored when M_30_110 and M_30_100 come        near each other and released when they separate towards their        rest state. This separation occurs exactly when the force        exerted by PC_30_350, PC_30_360 is at a minimum. No power needs        to be provided to PC_30_330 and PC_30_340, and they can possibly        be omitted. In general, embodiments of the invention, by        introducing magnetic fields in a general mechanism, introduce        energy storage in the mechanism. This stored energy function        e(x(t)) of the mechanism's current state x(t) can be cost        effectively designed with minima/maxima to offer control of        mechanism dynamics significantly decoupled from kinematics. In        addition, the invention offers additional control by having the        ability to inject power at multiple places, appropriate        controlled and sequences.

The ideas of powering at multiple joints (each possibly having reststates) can be applied to any mechanism with other kinds of joints(lower and/or higher pairs). Effectively, the mechanism is driven bymultiple prime movers, each directly moving different parts of themechanism, over possibly different portions of the cycle of themechanism. Since the percentage of power transmitted from one joint to adesired link, fineness of motion control, etc., varies depending on thestate of the mechanism, the joints and their powered coils can be soselected and powered in sequence to respectively maximize the powertransmitted to the output in all positions, improve fineness of control,etc. Exemplarily, states where no power is transmitted to the output canbe eliminated (so-called “dwell states”). In addition, the ability toselectively power different joints allows us to reduce peak forces andassociated stresses internal to the mechanism. This flexibility canminimize heavy reaction forces from the constraint surfaces, caused byactuation from a powered coil at a joint/link whose force is minimallytransmitted to the output link in the current mechanism state.

Generalization of Power Transmission Control

A generalized clutch is defined as a device causing transmission offorce causing relative motion to occur through any one of the joints inmechanisms (e.g., the six lower pairs or higher pairs). Transmission offorce through a revolute pair is a classical clutch well-known in thestate-of-art (for non-oscillatory transmission only). The inventiongeneralizes this to transmission of possibly oscillatory force from onelink to another connected through a general mechanism having any of thelower/higher pairs as joints. This has already been discussed. For anexample, force transmission using induction members and magnets isdepicted in FIG. 33 below

When reciprocating motion is transmitted by such generalized clutches,the motion transmission drops off at high reciprocating frequencies,beyond the bandwidth of the transmission of themagnetic/hysteresis/induction force, which can be calculated by standardtechniques of electromagnetics and dynamics (Section E). Design ofapparatus using the aforesaid generalized clutches has to properlyaccount for such effects.

Applications of this invention are many, including but not limited to:

-   -   Motion control in low-cost apparatus (SAs): The invention offers        low-cost non-uniform speed/timing/force/torque/position control        in mechanisms, compared to electronic techniques based on        closed-loop feedback, microprocessors, sensors, and servos.        Examples include tables to hold objects in moving environments        (e.g., a bottle holder for a car), read-head rest positioners in        disk drives, an extendible door, etc.    -   Design of highly reliable mechanisms (e.g., in        aircraft/spacecraft/mass transportation mechanisms/medical        equipment mechanisms) due to the ability to provide        cost-effective control speed of operation at all states of the        mechanism without using additional complexity in the mechanism        or sophisticated closed-loop control using        microprocessors/sensors/servos. The latter two techniques can        themselves decrease reliability due to the additional complexity        involved.    -   Design of high-precision mechanisms, positioning devices in        computerized numerical-control (CNC) machines, etc. Here,        sources of error due to mechanical backlash, zero-response zones        (dead-zones), etc., can be eliminated by having a high drive to        the mechanism together with a high inductive load. The drive        should be chosen to be much higher than minimum required to        eliminate backlash (much more than the “stick-slip” threshold).        An equally high induction load to the system will ensure very        slow, but non-zero motion (inductive load goes to zero at zero        velocity), which can be exploited to provide high accuracy.

The invention can be used in conjunction withmicroprocessor/sensor/servo based techniques and, in these situations,may help simplify the design of the closed-loop control system(exemplarily by reducing dynamic range, increasing response speed,reducing random disturbances, massaging the system open-loop response tobe close to that desired, etc.).

F. An Extended Example: 4-Bar Linkage and Reciprocating Mechanism

As a concrete example of all these ideas, FIG. 31 shows a 4-bar linkage,using magnets (permanent or electromagnets) placed on the mechanismlinks/joints (as multiple autonomously magnetic interacting members).The mutual interaction of the magnets, together with anyinduction/hysteresis members, determines rest positions and dynamics asper the discussion above in Section E. The joints can be revolute,prismatic (e.g., sliders similar to FIG. 33 below), or general. Poweredcoils placed on one or more of the links/joints will enable extensivecontrol of mechanism actuation for increased power, accuracy, etc. Forcetransmission between input link R_31_310 and output link R_31_320,modulated by rest states of the whole linkage and theinduction/hysteresis members (not shown) on P_31_400, constitutesgeneralized clutch action. We shall further elaborate on these ideasbelow in the important special case of a reciprocating slider-crankmechanism.

FIG. 32 shows a reciprocating mechanism, where a reciprocating shaftRS_32_340 (sliding in guide G_32_350) is shown attached by a pinDP2_32_330 to a connecting rod CR_32_320 driven by a prime mover. Theprime mover is exemplarily an electric motor, driving drive pinDP1_32_310 on drive disk DR_32_300 (this may be replaced by alternativemeans of drive).

An embodiment of Power Control as per the methods of Section B modulatesthe prime mover input to the mechanism. As discussed in Section B (e.g.,FIG. 10), use of an elliptical rotor provides torque that variesperiodically in each rotation. As such, appropriate orientation of theelliptical rotor major axis with respect to the drive pin DP1_32_310,enables time-varying position-specific power to be delivered to themechanism. In FIG. 32( a), the position of the mechanism is such thatthe elliptical rotor is aligned parallel to the main flux path,maximizing torque delivered to DR_32_300 and hence force toreciprocating shaft RS_32_340. A quarter rotation later (FIG. 32( b)),the elliptical rotor is perpendicular to the main flux path, minimizingforce delivered to RS_32_340. Thus, the force/speed/position/timing ofthe shaft RS_32_340 can be made variable by appropriately designing andorienting the elliptical rotor with respect to the mechanism. Theforce/torque variation can be made customizable and asymmetric at timeof use by the programmable ferromagnetic inserts shown in FIGS. 10( c)and (d). Multiple prime movers can also be used, e.g., adding one ormore coils on the guide G_32_350 for RS_32_340 to move RS_32_340directly.

An embodiment of Power Transmission Control (FIG. 33) attaches magnetM_33_100 (or a magnet assembly M_33_100 as per Section A) to connectingrod CR_33_320 in the vicinity of the drive pin DP2_33_340. The drive pinDP2_33_340 is omitted (or modified), and auxiliary constraints keepingconnecting rod CR_33_320 in the vicinity of reciprocating shaftRS_33_330 are present. The reciprocating shaft RS_33_330 incorporatesone or more magnets/induction/hysteresis members of various kinds, asper Section A. Exemplarily, a slot is cut in RS_33_330, in whichDP2_33_340 can slide, yielding a prismatic joint or a higher pair. Thejoint between DP2_33_340 and RS_33_330 is a higher pair (line contact)unless DP2_33_340 is free to rotate around CR_33_320 with a revolutejoint, in which case DP2_33_340 can slide with surface contact overRS_33_330 forming a prismatic pair. If it is a higher pair, then theslot need not be a straight line, but can be a general curve. Novertical force is transmitted through this joint. Vertical force is dueto induction in RS_33_330 due to field from magnet M_33_100 (or magnetsM_33_100). Note that, instead of the configuration shown, magnetM_33_100 can be on RS_33_330 and the induction member can be onCR_33_320, or both the magnet and the induction member can be on bothRS_33_330 and CR_33_320.

Electromagnetic force is produced in RS_33_330 due to induction causedby slip between CR_33_320 and RS_33_330. One major advantage ofinductive power transmission control is fail-safeness. If RS isprevented from motion due to an obstacle, excessive guide friction,etc., the rest of the mechanism can continue to operate. The transmittedforce will increase, because the slip is maximum when RS_33_330 isstationary, but the mechanism will not stall or “jam.”

FIG. 34 shows an embodiment of Load Control, which attaches an inductionmember IM_34_200 to connecting rod CR_34_320. This induction memberIM_34_200 is a conductive strip, whose geometry and dimensions (length,width, thickness, etc.) are determined to obtain the desired brakingforce, as per the description in Section A. The induction memberIM_34_200 may be identical to the connecting rod CR_34_320 and may alsobe any of the pins DP1_34_310 or DP2_34_340. Instead of an inductionmember, a hysteresis member or autonomous sources of magnetic flux (e.g.magnets) can be used, as per Section A. If magnets are used (as in FIG.36), the Load Control becomes dissipationless. That is, the loadperiodically absorbs and returns energy to the apparatus, whilemodulating speed.

At a desired position of this reciprocating mechanism, the conductivestrip IM_34_200 passes over a magnet M_34_100 (or magnet assemblyM_34_100 as per Section A), developing opposing electromagnetic force(inductive), which slows the mechanism down. This causes the mechanismto spend more time in those positions when the strip IM_34_200 is overthe magnet M_34_100, resulting in control of the timing of thetrajectory of the whole assembly, in particular reciprocating shaftRS_34_330 (exactly analogous to the previous discussion for thetiming-control induction member of FIG. 20).

FIG. 35 shows the waveform of the position of the reciprocating shaftRS_34_330 over time, which periodically oscillates between positions X0and X2, via intermediate position X1. In the absence of the conductivestrip IM_34_200, the mechanisms goes from position X1 to X2 in a shorttime between T0 and T1. In the presence of the conductive strip, thetime to go from position X1 to X2 is lengthened to the interval betweenT0 and T2 (IM_34_200 is over magnet/magnets M_34_100 sometime duringthis interval), thus “flattening” the waveform of position with time.Arbitrary time waveforms can be obtained using a suitable number ofinduction/hysteresis members like IM_34_200, a suitable number ofmagnets, and appropriate geometry and dimensions (length, width,thickness), material type, and material solidity, slottedness, orperforatedness as appropriate (as per the discussion in Section A). Theforce can be programmably generated by providing slots for bothinduction/hysteresis members like IM_34_200 and magnets M_34_100, sothat the timing behavior of the mechanism can be changed as required.

A variant of Load Control is shown in FIG. 36, where, instead of theinduction member, two magnets M_36_100 and M_36_110 are used. M_36_100is mounted on the connecting rod CR_36_320, while M_36_110 is mountedtogether with the cylinder G_36_350 on mounting frame MO_36_400(exemplarily at a depth below M_36_100). The apparatus may be used fordamping vibrations in an IC-engine. Magnets M_36_100 and M_36_110 havelike poles facing each other (when they come close) and are so arrangedto come close to each other at the end of the power stroke (with theflywheel F_36_300 as shown), absorbing energy from the prime mover (thegas force from the piston). During continued rotation of F_36_300,M_36_100 and M_36_110 repel each other (the rest state of the mechanismhas flywheel F_36_300 one half rotation displaced from the end of thepower stroke), releasing energy, compensating for the lack of powerduring the exhaust stroke. The geometry of M_36_100 and M_36_110 maydiffer from the illustration, and there can be multiple magnets on boththe mounting MO_36_400 and the reciprocating mechanism, designed andarranged to minimize torque ripple (as shown on the mounting in the samefigure). The same ideas in vibration minimization, whether usingdissipationless magnetic attraction/repulsion or damping forces based oninduction and/or hysteresis, can be applied to shock absorbers. Longlever arms or speed-increasing gearboxes can be used to increase theforces/torques. An exemplary illustration is described later for ageneral hinged device (see FIG. 53 showing a bin lid).

All three forms of control to this mechanism, Power Control, PowerTransmission Control, and Load Control, admit of all the variants usingpossibly hysteresis effects, multiple autonomously magnetic interactingmembers, magnet/induction/hysteresis members of different geometry,etc., as per Section A. Note that, with hysteresis members and multipleautonomously magnetic interacting members, the mechanism has preferredrest positions, which have to be accounted for during design.

G. Apparatus Using the Invention

To illustrate the wide applicability of the invention, we describeadditional exemplary apparatus using the ideas outlined in Sections A-F,including uniform motion control, non-uniform motion timing control,with and/or without user programmability, and motion control in generalmechanisms. The ideas can be applied in other apparatus, and theinvention extends to them. Without limitation, the invention can beapplied to enhance the functionality of the following apparatus:

-   -   A bubble toy, demonstrating vibrations of minimal surfaces        (e.g., FIGS. 37-39).    -   A vibration bench, whose vibration velocity profile, and hence        vibration spectrum, can be controlled to suit, generating        harmonics as desired. This ability to generate arbitrary        vibration spectra can be also applied to food processors,        washing machines, agitators, etc. This same ability to control        reciprocation velocity, in a dissipationless fashion, can be        used in metal-working presses for punching, forging, etc. In        this case, the velocity/force exerted on the metal can be        accurately controlled as a function of time or position of the        stroke. The inverse-damping of vibrations can be applied to        shock absorbers.    -   A paper dispenser, which is enhanced to prevent excessively        rapid rotation of the paper roll to prevent wastage (e.g., FIG.        40).    -   A well pulley with an induction brake to prevent the water        vessel from dropping excessively fast (e.g., FIG. 41).    -   A display turntable, whose rotation speed can be controlled to        provide best viewing to customers/onlookers (e.g., FIG. 42). The        same ability can be used to control rotation speed in water        sprinklers, pedestal/table fans, etc.    -   A display turntable, whose non-uniform rotation-speed profile        can be programmably changed by the user for best display effect        (e.g., FIGS. 43-44). The same ability can be used to        programmably control rotation speed and direction of action in        water sprinklers, pedestal/table fans, etc.    -   A lazy-Susan type device, which is enhanced to provide a smooth        resistive force to prevent excessively rapid rotation of the        device (e.g., figures same as display turntable).    -   A rotating doll whose speed of uniform rotation can be        user-controlled, or a rotating doll whose non-uniform rotation        speed can be both user-controlled as well as whose        non-uniformity be user-programmed (e.g., FIG. 45).    -   A rotating lollipop dispenser, having speed control built in,        enabling the lollipop taster to rotate the lollipop at different        desired speeds relative to the tongue (e.g., FIG. 46).    -   A timing CAM based on electromagnetic force principles (e.g.,        FIG. 47). This same device can be used in an anti-lock braking        system providing pulsating braking forces whose pulse shape and        frequency can be controlled as desired.    -   A powered toothbrush, providing low-cost, continuously variable        speed control to the user (e.g., FIG. 48).    -   A toothbrush mechanism, which “automatically declutches” at        excessively high load.    -   A toothbrush mechanism, whose brushing velocity profile can be        controlled to yield maximum user comfort.    -   A toy racing car, where the resistive speed control is replaced        by a continuously variable induction/hysteresis speed control        using our techniques.    -   A set of toy racing cars, which can co-operatively/competitively        race, based on the attraction/repulsion of high-strength magnets        on them. Here, the rest states of the set of cars could be        convoys of cars with the north pole of one car sticking to the        south pole of another car, etc.    -   A set of toy racing cars, racing synchronously due to magnetic        attraction/repulsion.    -   A fan or electric razor, providing continuously variable speed        control to the user based on the motion control techniques.    -   An electric razor, providing a shaving profile that slows down        when the blade is beginning to cut and speeds up after cutting,        based on motion control of general mechanisms (Section E).    -   A drawer, which is enhanced to prevent violently rapid        opening/closure, increasing both safety and reducing wear and        tear of the unit (e.g., FIG. 49).    -   A CD latching/ejector mechanism, which is enhanced to eliminate        excessively violent action (FIG. 50).    -   Any hinged device, which is enhanced to prevent slamming (e.g.,        FIG. 51), including but not limited to (a) a door closer, (b) a        oven door closer, (c) a toilet seat, (d) a suitcase lid, and (e)        a lid for a plastic bin. In these apparatus, gear/lever        mechanisms can be used to enhance force/torque (FIGS. 52-54).    -   A rotating chair, which is enhanced to have an induction disk in        proximity with magnets to avoid rotation “overshoot.”        Alternatively, the chair could have a non-uniform ferromagnetic        hysteresis disk or a disk with multiple magnets, inducing        preferred rest positions in the chair.    -   A coat hanger and coat hanger rail, which is enhanced to include        magnets in either the coat hanger and/or the coat hanger rail to        prevent the coat hanger from occupying undesirable “twisted”        positions on the rack.    -   A toilet flush tank, which has a magnet attached at the top, to        enable steel napkin holders to be held firmly and not “slip-off”        the tank.    -   A car dashboard with a magnet attached in the middle, to enable        ferromagnetic objects to be conveniently held in place and not        “slip off.”    -   A circular pedestal with a ferromagnetic material on the        surface, to which platforms can be attached at various        heights/angles magnetically to hold objects, exemplarily flower        pots (e.g., FIG. 55).    -   A pedestal with a spherical ferromagnetic surface, to which        platforms/clips can be attached at various positions to hold        objects e.g., pens, pencils (e.g., FIG. 56).    -   A magnetic shower attachment device, which has a showerhead        attachment with a magnetic base attached to a ferromagnetic        strip on the bathtub. This enables the showerhead to be placed        at any desired height. Using a grooved ferromagnetic member        projecting from the bathtub enables both the height and angle to        be varied.    -   A magnetic wire-clipping device, which has a clip attached to a        magnetic base to enable wiring traditionally placed on the floor        to be conveniently organized and routed at appropriate paths on        the walls or the floor, without the necessity to drill holes        (e.g., FIG. 57).    -   A board game (e.g., carom/billiards/snooker) enhanced by the use        of magnetic/induction/hysteresis members (e.g., FIG. 58).    -   An extendible tether/noiseless ratcheting door with gentle        noiseless operation (e.g., FIG. 59).    -   An aircraft taking off and landing without power (e.g., FIG.        60).    -   A contactless manipulator assembling general products (e.g.,        FIG. 61).    -   Any clothing utilizing a magnetic button and a metal backing,        which enables the appropriate degree of tightness to be achieved        based on the individual's current dimensions.    -   A field-limiting device to reduce leakage fields from affecting        articles of household use.    -   A bearing, which has built-in induction load to reduce        excessively high-speed rotor operation, as per the methods of        Section D. The use of unidirectional nonlinear members like        diodes in the current return path enables the bearing to exhibit        speed limiting in only one direction.    -   A gear, whose speed-torque transmission characteristics can be        user-programmed and are not necessarily in inverse proportion        (e.g., FIG. 12).    -   A reciprocating mechanism, which does not “seize” at        unexpectedly high load (e.g., FIG. 33).    -   A Geneva mechanism with contactless engagement (similar to the        reciprocating mechanism of FIG. 33).    -   A robotic device, which is “fail-proof” and disengages smoothly        in situations that are outside the capabilities of its        kinematics (e.g., FIG. 33).

While the apparatus will be described primarily using induction forces,they admit of all the variants using possibly hysteresis forces,multiple autonomously magnetic interacting members,magnets/induction/hysteresis members of different geometry, etc., as perSection A. Predominantly, we shall use Load Control (as per Section D),but Power Control (as per Section B) and Power Transmission Control (asper Section C) can also be used for powered devices, and the inventionapplies equally to those variants as well.

Although certain embodiments of the invention are shown in the examplesbelow, it should be distinctly understood that the invention is notlimited thereto but maybe variously embodied within the scope of theclaims specified in the claims section.

Bubble Vibration Toy, Demonstrating Vibration of Minimal Surfaces

The apparatus in FIG. 37 shows vibrations of soap films, formingexciting patterns interesting to children and others. Driving wheelR_37_310 is driven by an electric motor, whose speed is controlled bymagnet M_37_100 (or magnets M_37_100) interacting with induction memberIM_37_200, as well as possibly other induction/hysteresis/autonomouslymagnetic members. Driving wheel R_37_310 is connected to reciprocatingshaft RS_37_370 via crankshaft CR_37_360. Soap film frame SF_37 _300 isattached to reciprocating shaft RS_37_370 and set into oscillatorymotion by it at a rate controllable by modulating the induction forcegenerated in induction member IM_37_200 using any of the techniquesoutlined previously in Section A. Instead of IM_37_200, other inductionmembers, including an induction disk attached to the driving wheelR_37_310, can be used and the force/torque controlled following themethods in FIGS. 14-19. When the oscillation rate is equal to anyresonant frequency of the soap film, large vibrations can be noticed bythe viewer. Instead of a rotating electric motor driving R_37_310,CR_37_360, and then RS_37_370, a linear motor may be used to driveRS_37_370 directly. If lossless speed control is desired, thenautonomously magnetic members may be used.

FIG. 37 depicts a vibration toy using a circular soap film frame,exemplarily made of thin plastic using injection molding. Other shapesare also possible, including rectangles (e.g., FIG. 38( a)), cubes(e.g., FIG. 38( c)), octahedral, other 3-dimensional, etc. Theoscillations can be up-down, sideways, angular (e.g., twistingrepeatedly back-and-forth as in FIG. 38( d)), and in general a multipledegree of freedom oscillation e.g., 3-axis translational and/or up to3-axis rotational oscillation. The frame may have symmetry (e.g., acircle) or may have a slight asymmetry, which, in FIG. 38( b), isexemplarily a projection P_38_300 to break the degenerate nature ofhigher-order resonant modes with respect to angular position for stableviewing. The frames may oscillate or be stationary with one or moreauxiliary members of arbitrary geometry attached to the same soap filmoscillating. For example, in FIG. 38( e), E_38_300 vibrates, whileSF_38_310 is stationary. If both oscillate at possibly differentfrequencies “standing-waves” are generated in the soap film. In general,multiple frames may simultaneously excite the same soap film, atpossibly different frequencies, showing beat patterns. The frames mayhave multiple portions of different resonant frequency, and changing theoscillation frequency will selectively excite different portions, makingthe viewing interesting. For example, in FIG. 39, SF_39_310 is a smallersquare than SF_39_300, and oscillates at a higher frequency. Changingthe oscillation frequency from low to high will first cause SF_39_300 tooscillate at its fundamental, and then SF_39_310 will oscillate(together with the other two small frame portions). As frequency isfurther raised, each structure will resonate whenever frequency matchesone of the resonant frequencies of the structure. Changing frequency ina “musical” manner will make different frame portions vibrate atdifferent times, making the soap film oscillations “dance” betweendifferent frame portions.

Many variants of the soap bubble vibration toy exist, including:

-   -   The means of vibration can be a general mechanism (not just the        reciprocating shaft illustrated) and may include multiple moving        members, each having in general multiple degrees of freedom,        e.g., 3-axis translational and 3-axis rotational motion.    -   The excitation need not be purely sinusoidal and may have        different frequencies exciting different portions of the frame.        Cost-effective methods of generating motion having arbitrary        frequencies have been described in Section E.    -   The motion need not be rigid, with the dimensions and/or shape        of the soap film frame itself varied using flexible structures        for them. Exemplarily, the soap film frame can be a 4-bar        linkage. This provides an excellent illustration of parametric        oscillations in membranes.    -   The soap films can be preferably viewed in strong, possibly        polarized light to illustrate the vibrations clearly.    -   The whole apparatus can be hand-held or arranged to be        conveniently placed on tables, attached from ceilings, etc.,        with appropriate lighting arranged.    -   The diamagnetic properties of water can be exploited by bringing        strong magnets (e.g., neodymium magnets) near the source of        vibration, changing the shape of the vibration surface due to        the exertion of diamagnetic repulsive force on the membrane. The        magnets can be part of the frame structure itself, arranged in a        manner to impinge strong fields on the soap films attached to        the surface.    -   Instead of soap films, thin latex rubber membranes can be used        as the oscillating structures. Alternatively, elastic cords can        be used for one-dimensional vibrations. In either case, the        membranes can be loaded at different points to change the        resonant behavior. Moreover, the membrane can be partially        and/or completely coated with a highly reflective substance to        create a pleasing lighting pattern, changing with the vibrations        of the membrane.

If, in FIG. 37, instead of the soap film frame SF_37_300, we have avibration table attached to shaft RS, a vibration testing jig isobtained, whose timing and hence vibration spectrum can be controlled.The spectrum of the vibration can be controlled at far lower costcompared to microprocessor-based servos, possibly at the expense of someaccuracy and flexibility. The ideas can be applied to presses, e.g., forpunching, forging, forming, etc., where the stroke force/speed profilecan be accurately and predictably controlled during the entire stroke(forward, return, etc.). The same ideas can be applied to foodprocessors, which can have their attachments display a “jerky” motionwith high frequencies for improved food processing (mixing, mashing,cutting, etc.). The same ideas can be applied to washing machines, whoseagitators can be designed to have high-frequency motion components todislodge dirt more effectively.

Paper Roll Dispenser with Induction Speed Limiting

FIG. 40 shows a paper roll dispenser with an induction member I_40_200revolving on a dispenser shaft having a sleeve on which the paper rollPR_40_300 is mounted using, e.g., a friction fit. The positioning of themagnet structure M_40_100 with respect to the paper roll can be asdesired to prevent interference to paper dispensing. Alternativestructures can be used to provide inductive braking force to the paperroll. The apparatus can provide the following advantages:

-   -   A large quantity of paper cannot be jerked out of the roll,        minimizing wastage.    -   When the roll is spun to release the free end of the paper        sheet, the risk of the roll over-spinning and releasing a large        length of paper is greatly reduced.    -   Easier paper cutting, since the induction disk provides a        restraining force.        By using an appropriate induction member, the restraining force        can be changed during a cycle (as described in Section A and        shown in FIG. 20). For example, the force can be increased to        facilitate cutting of the paper, and then reduced to facilitate        unrolling, etc.

Well Pulley with Induction Speed Limiting and/or Attached Dynamo

FIG. 41 shows a pulley WP_41_300 for a water well, having an inductionbrake I_41_200 attached to the pulley shaft. The water vessel tied tothe rope (not shown for clarity) is restrained from dropping excessivelyfast into the well by the induction brake shown, designed as per SectionA. This is especially beneficial to prevent living creatures in the wellfrom being hurt by excessively high-speed impact of the water vessel, aswell as to prevent damage to the water vessel itself by impact on rocks,etc., on the water floor, especially during dry seasons. Additionally,the potential energy of the water vessel can be harnessed by convertingthe induction brake into a dynamo.

Rotating Display Turntable with Variable Speed Control

FIG. 42 shows an exemplary display turntable, where a prime mover(exemplarily an electric motor, not shown) drives axle A_42_310,possibly through a gearing mechanism. An arrangement of magnetsM_42_100, inducing eddy-currents (or hysteresis effects) in inductionmember IM_42_200, enables the speed of rotation of the display shelfDS_42_300 to be controlled as desired. In an alternative embodiment, theprime mover drives DS_42_300 through a gearing mechanism, and theinduction member IM_42_200 is located on the motor shaft, yielding highforce/torque due to high speed rotation. The configuration of theinduction member and magnets can be varied as described in Section A.

This apparatus can provide the following advantages:

-   -   The rotation speed can be changed in a smooth manner, using        methods outlined in Sections A-D. Indeed, the customer/viewer        can be given control to vary the speed to suit.    -   The display can be directly driven by a motor without a gear        train, provided sufficient induction force is generated by the        magnets and induction member.

Without a prime mover (e.g., display moved by hand), we get a lazy-Susanturntable, and the invention applies equally to that apparatus. Insteadof the display platform, if we have a water sprinkling head, we get awater sprinkler, whose speed of rotation can be controlled to suit.Replacing the display platform by a spool on which wire can bewound/rewound under, e.g., the power of a winding spring results in acord rewinder (of use, for example, in vacuum cleaners) that can windwire at a speed which can be set by the user. Attaching a fan to theplatform enables the breeze to be swept at a desired pace throughdifferent portions of the room (the same can be done for oscillatingfans, using control of speed of the oscillating mechanism as per SectionE).

Rotating Display Turntable with Cutout and Variable Timing Control

In FIG. 43, the display turntable has an induction member IM_43_200 witha cutout, which enables quick “return” of the display objects frompositions where they cannot be conveniently viewed. FIG. 43 shows a casewhere we have a price sheet behind the objects. When the back of theprice sheet appears in front, the display turntable turns fast tomaximize the amount of time the viewers (assumed to be in front) areable to view the displayed items. The induction member can havedifferent cutouts, possibly multiple, with varying thickness, slots,perforations, may be of different materials, etc., as outlined inSection A. In an alternative embodiment, the prime mover drivesDS_43_300 through a gearing mechanism, and the induction memberIM_43_200 is located on the motor shaft, yielding high force/torque dueto high-speed rotation. Cutouts can be located on IM_43_200 to obtainhigh-frequency variations of speed, and auxiliary mechanisms can be usedto move M_43_100 exemplarily either axially or radially to obtain slowercontrol of speed (see the discussion of the timing CAM of FIG. 47( c).Several induction members and magnets of different properties can bejointly used, as also outlined in Section A.

Without a prime mover (e.g., display moved by hand), we get a lazy-Susanturntable, and the invention applies equally to that apparatus. Insteadof the display platform, if we have a water sprinkling head, we get awater sprinkler, whose speed of rotation can be controlled in anon-uniform fashion to preferentially water certain areas. Replacing thedisplay platform by a spool on which wire can be wound/rewound underexemplarily the power of a winding spring results in a cord rewinder (ofuse, for example, in vacuum cleaners) that can wind wire at anon-uniform speed whose average can be set by the user. Attaching a fanto the platform enables the breeze to be swept at a non-uniform pace,through different portions of the room. The average pace can be set asdesired. The same can be done for oscillating fans, using control ofspeed of the oscillating mechanism as per Section E.

Rotating Display Turntable with Programmable Cutout

In FIG. 44, the display turntable has an induction member IM_44_200 witha programmable cutout as per Section A, Section D, and FIG. 24, whichenables the quick-return and slow-display portions to be chosen by theuser, after positioning the display objects. Thus, objects havingdifferent angular extents can each be conveniently positioned and shownfor the optimum amount of time. In an alternative embodiment, the primemover drives DS_44_300 through a gearing mechanism, and the inductionmember IM_44_200 is located on the motor shaft, yielding highforce/torque due to high-speed rotation. Programmable cutouts can belocated on IM_44_200 to obtain high-frequency variations of speed, andauxiliary programmable mechanisms can be used to move M_44_100exemplarily either axially or radially to obtain slower control of speed(see the discussion of the timing CAM of FIG. 47( c)). Thisprogrammability can exemplarily be the ability to insert metallicmembers in slots (as in FIG. 24), but instead of generating inductionforces, these metallic members move the position of magnet assemblyM_44_100. In general, there can be multiple magnets and multipleinduction members, some or all of which can be programmably changed asper Section A, Section D, and FIG. 24.

Without a prime mover (e.g., display moved by hand), we get a Lazy Susanturntable, and the invention applies equally to that apparatus. Insteadof the display platform, if we have a water sprinkling head, we get awater sprinkler, whose speed of rotation can be controlled in anon-uniform user customizable fashion, to preferentially water certainareas. Replacing the display platform by a spool on which wire can bewound/rewound under exemplarily the power of a winding spring results ina cord rewinder (of use, for example, in vacuum cleaners) that can windwire at a non-uniform speed whose time profile can be set by the user.Auxiliary mechanism (see the CAM discussion in FIG. 47( c)) can bearranged to make the entire apparatus act only at the extremities of thecord to prevent either yanking the cord out of the spool on one end, ora power plug at the other end from hitting a stop very hard. Attaching afan to the platform enables the breeze to be swept at a non-uniform pacethrough different portions of the room. The detailed timing can be setas desired. The same can be done for oscillating fans, using control ofspeed of the oscillating mechanism as per Section E.

Rotating Doll

The doll of FIG. 45 rotates at a speed that can be viewer-controlled,using controllable induction force generated by an induction memberIM_45_200 interacting with one or more magnets M_45_100. The motion maybe uniform or non-uniform, and may be optionally changeable by the userby the insertion of optional induction members in slots provided forthis purpose, as discussed in Section A, Section D, and FIG. 24.Exemplary embodiments of this apparatus are:

-   -   A rotating doll, whose rotation speed can be user-controlled,        with multiple viewing positions (multiple cutouts). The doll can        face more than one viewer at different positions for the maximum        length of time.    -   A rotating doll, whose rotation speed can be user-controlled,        with programmable, multiple viewing positions. This doll can        face an arbitrary number of viewers at different positions for        the maximum length of time.

The resultant timed motion may be utilized for many purposes,exemplarily, production of musical notes by other apparatus (not shown)attached to doll apparatus. For example, music can be played byattaching a circular tuning fork with teeth to the axle, whichperiodically contact a stationary hammer. A rotating switch on the axlecan make lights blink, etc. In general, any timed,electrical/mechanical/acoustic waveform can be generated from the timedmotion.

Rotating Lollipop

FIG. 46 shows a lollipop that rotates at a speed that can betaster-controlled, using controllable induction force generated byIM_46_200 in the presence of magnets M_46_100. Use of multiple cutoutsin the induction member as discussed in Section A, Section D, and FIG.24 enables the speed of rotation to be varied in a single cycle for morevariety.

Multi-taste “lollipop sundaes” can also be made and automatically tasted(e.g., sweet 50% of the time, sour 10%, hot 40% of time). The lollipopmay be different from the illustration, e.g., it can have an inner sweetcore, surrounded by shells of sweet, sour, and hot, etc. The speed ofrotation will determine the speed of transitioning from hot to sweet andthe “dwell time” on any taste, thus adding more variety.

Magnetic Cam

The timing control disk R_21_200 of FIG. 21, rotating around axleA_47_400, can be alternatively regarded as a CAM. By driving A_47_400,with e.g., a constant torque, this CAM generates any desired function ofangular position of axle A_47_400 over time (as in FIG. 47( b)), byappropriately controlling the braking forces/torques, as per SectionsA-F. For example, the braking force in slotted area SL_47_300 isintermediate between the full cutout and the solid portion. Ifautonomously magnetic members are used, the timing is changed in adissipationless manner.

FIG. 47( c) shows a variant, where an auxiliary mechanism Me_47_500,connected to both axle A_47_400 and magnet M_47_100, simultaneouslymoves magnet M_47_100, for example, outwards relative to axle A_47_400.FIG. 47( d) shows the resultant angular position of axle A_47_400 as afunction of time. The angular position shows periodic variationscorresponding to rotation of axle A_47_400, and a general slowing downdue to movement of magnet M_47_100, offering more timing control. Themechanism Me_47_500 can move M_47_100 in a cyclic manner also (radiallyor axially outwards, inwards, outwards, inwards, etc.). If R_47_200 isan induction member, then it can be rotated at high speed to generatehigh force/torque, while average timing is changed at a slower period bythe mechanism Me_47_500. FIG. 47( e) shows the resultant pulsatingbraking force/torque, whose average increases (assuming a constanttorque drive to axle A_47_400). This ability to independently controlaverage force and timing is very useful in many apparatus liketurntables, drawers, etc., where the force required can be high andsimultaneously the operation cycle is long. The ability to generatepulsating forces is applicable to automobile anti-lock brakes. IndeedFIG. 47( c) can depict an automotive anti-lock brake system, wheremechanism Me_47_500 is the brake control, and R_47_200 is a slottedinduction disk, e.g., slotted uniformly at its circumference. Pulsatingforces, whose pulse shape and magnitude as a function of wheel angularposition can be accurately controlled and changed in milliseconds can beobtained for anti-lock braking, faster than existing hydraulic systems.The apparatus, since it can be used with permanent magnets, potentiallyoffers higher reliability than alternatives using electromagnets oncompletely solid induction members (the two methods can be used inconjunction). The outward motion of magnet M_47_100 relative to A_47_400can be replaced by any of the variants (e.g., axially outward motion asin FIG. 3, flux path reluctance change as in FIG. 5, etc.), andhysteresis/autonomously magnetic members can also be used, as describedin Sections A-F.

All this creates a new apparatus, a CAM based on magneticattraction/repulsion and/or induction/hysteresis principles, whosetiming/force profile can be designed to suit, possibly in a programmablefashion.

Toothbrush with Speed Control

FIG. 48 shows a powered toothbrush, exemplarily powered by 2 AA/AAAbatteries. The motor rotation is converted by a general mechanismME_48_300 to the brush-head's rotation/oscillation. Speed control isachieved by apparatus SC_48_400 following the techniques in SectionsA-E. Motor (and hence brush-head) speed can be controlled in a smoothand non-stick fashion, using the speed-control techniques outlinedpreviously, in any of its variants (Sections A-F). Various embodimentsof this invention include the following:

-   -   Using an induction disk with magnets that can be moved axially        or radially using mechanical means well known in the state of        art. This enables the brush speed to be controlled for best        brushing comfort.    -   Using cutouts in the induction disk, which enables speed to be        changed at different positions of the brush head, thus        increasing brushing comfort even more. If the induction disk is        connected to the drive shaft of the motor, the speed        periodically varies with each motor revolution.

Using induction members and magnets in the mechanism connecting themotor shaft to the brush head, which enables the speed of the brush-headmovement to be controlled in a possibly non-uniform fashion for maximumcomfort. Depending on the location of the magnets and induction members,the speed variation may be periodic with each motor revolution, periodicwith each oscillation/rotation cycle of the brush head (typicallylower), etc. The design of the magnets and induction members, for anydesired speed variation of the brush head, is as per the discussion ongeneral mechanisms in Section E.

-   -   Using programmable cutouts in the induction disk or induction        member (in the brush-head mechanism) enables the user to        customize the speed profile of his or her brush for maximum        comfort.    -   Use of Power Transmission Control in the form of an eddy-current        clutch enables the mechanism to smoothly disengage if the brush        head encounters too much resistance in the mouth, enhancing        safety.    -   Use of a hysteresis member or multiple autonomously magnetic        interacting members can allow rest states of the toothbrush to        be as desired. In one embodiment, the bristles can be        magnetically “retracting” in a rest position for safety,        emerging only during brushing.

While we have shown one embodiment, where the drive to the motor isdirectly from the battery, this is not necessary. The motor drive mayitself be modulated by electronic techniques well known in the state ofart (e.g., pulse-width modulation), especially at higher voltages (e.g.,3-4 batteries).

Drawer with Induction Brake

FIG. 49( a) shows magnet/magnet assemblies M_49_100 (attached to a tablenot shown) inducing eddy currents in induction member (a strip or adisk) IM_49_200 attached to the side of a drawer. The generatedinductive force slows down drawer opening/closing. There can be multipleinduction members on the side of the drawer to generate retarding forceat various desired drawer positions. Gears may be utilized to increasethe relative velocity between the induction members and the magnets, asdescribed below with regard to the hinged device. For example, in FIG.49( b), the drawer glide wheel GW_49_300 is attached to aspeed-increasing gear train (details omitted) driving the induction diskIM_49_200. Magnet M_49_100 installed on the drawer support generateslarge braking forces in those positions of the drawer that causeIM_49_200 to come near M_49_100.

For example, the drawer motion can be braked near the completely openand/or completely closed positions. Drawer opening/closing speed can beregulated using all the force control methods outlined previously (e.g.,Sections A, D, and E). The stray magnetic fields generated can bereduced by magnetic shielding using back-iron, etc., well known in thestate of art.

Ejector/Latching Mechanism

The invention can be applied to controlling the ejection speed inejectors (latching speed in latches), using induction/hysteresis/forcesor forces between multiple magnets. This is very useful in (1) floppydisk/CD/DVD drives to prevent floppy disks/CD/DVD's from being violentlyjerked out during the ejection process, (2) tape/VCR players to preventthe tapes from being violently jerked out, etc. In addition, thepotential to control mechanism speed can enhance reliability of thesedevices.

FIG. 50 shows such an embodiment, where an induction member IM_50_200 inproximity with a magnet M_50_100 applies braking force to the disk orthe disk carrier during ejection. Force is also applied duringinsertion, but that is typically much less due to the low insertionspeeds. The high speed during “latching” of the CD (CD_50_300) can alsobe controlled using the same or additional induction members and/ormagnets. For floppy drives/VCR's, the induction members can be attachedto the mechanism members themselves, since carriers are not typicallyused for these devices. In summary, the speeds of the entire mechanismand all attachments (disks, tapes, etc.) can be regulated to enhancesafety and reliability. Exemplarily, switches that do not “snap”suddenly can be designed. The same ideas can be applied to foodprocessing items like bread toasters, where the toast will come upgently, based on the ejector mechanism being braked. Similarly,umbrellas that open slowly can be designed.

The mechanism admits of all the variants using possibly hysteresiseffects, multiple autonomously magnetic interacting members,magnet/induction/hysteresis members of different geometry, etc., as perSection A.

Hinged Device

FIG. 51 shows a hinged device HD_51_310, rotating around hinge H_51_300being “braked” when induction member IM_51_200 is near magnet (magnets)M_51_100. HD_51_310 can exemplarily be:

-   -   (a) A door,    -   (b) An oven door,    -   (c) A car door, car trunk door, car hood,    -   (d) A washing machine door,    -   (e) A toilet seat,    -   (f) A suitcase lid, or    -   (g) A lid for a plastic bin.        Additional mechanism may be present to transmit the hinged        device HD_51_310's motion to the induction member. For example,        a long lever arm or a gear system (with one or more gears) may        be used to give a higher speed to the induction member, and        hence higher force/torque (e.g., the bin lids in FIGS. 52-54).        The force/torque can be non-uniform, following any of the        techniques described previously (e.g., Sections A, D, and E).        For example, in FIG. 52, induction member IM_52_200, and magnet        M_52_100 are both at the edge of the lid, resulting in higher        speed, force and torque. In FIG. 53, induction member IM_53_200        is driven at higher (angular) speed than the bin lid by the use        of a gear train (speed-increasing gear train). Torque on bin-lid        hinge H_53_300 increases due to both (1) higher speed of        induction member IM_53_200 relative to magnets M_53_100 and (2)        gear train lever arm (mechanical advantage). Gears G_53_400        (large) and G_53_410 can be of any type, where spur gears are        shown in the illustration.

FIG. 54 shows a variant using multiple gears. Gears G_54_400, G_54_410,and G_54_420 are shown, along with two induction members IM_54_200 andIM_54_210 and associated magnets M_54_100 and M_54_110. The presence oftwo induction members and associated magnets allows increased control ofthe torque exerted by the system on hinge H_54_300, as a function ofangular velocity of the aforesaid hinge H_54_300. The presence of two(in general, multiple) magnets and associated induction members enablethe decrease of force at very high speeds, due to the skin effect to becompensated for. In this example, IM_54_200 rotates at a higher speedcompared to IM_54_210, and hence encounters the skin-effect forcereducing speed regime earlier. In this situation, the continued increasein force of IM_54_210 with respect to speed provides partialcompensation for the reduction in force of IMP_54_200.

Adjustable Height/Angular Position Pedestal for Flower Pots and OtherObjects

This is an example where undesirable motion should be prevented. FIG. 55shows a pedestal F_55_300 with a ferromagnetic material on its surface(e.g., iron plate) and with magnetically attached platforms (withmagnets and flux return paths), whose heights can be varied anywhere onthe pedestal. Pots and other objects can be placed on the platforms, andthe heights varied as desired. Magnetic field modulation techniques asper Section A, where pole pieces can be inserted, the magnetic fluxreturn path changed, etc., can be used to quickly attach and/or releasethe magnetic platforms from the pedestal. To increase holding force, themagnets may have both north and south poles contacting the ferromagneticpedestal surface.

Stability of attachment can be provided in several ways. Mechanicalguides/slots can be provided to prevent the pots from tipping oversideways and also provide additional support to prevent the magnets fromcoming loose from the pedestal. In another embodiment, the surface ofboth the pedestal and the magnets can have matching grooves,projections, or general texture. In FIG. 56, for example, the surface ofthe pedestal F_56_300 can have shallow grooves into which smallprojections from the surfaces of the magnet/magnets M_56_100 fit snugly.

In addition to height, the angular position of the platforms can beadjusted if (1) a cylindrical ferromagnetic pedestal is used (e.g., asteel pipe) and/or (2) magnets and flux return paths having acylindrical surface exactly matched to the pedestal (including anygrooves/projections/texture) are used. The same idea can be embodied ina spherical pedestal with ferromagnetic material possibly withgrooves/projection/texture on the surface providing attachment toplatforms/clips, which have magnetic attachments to the surface. Thesurfaces of the magnets will have projections/grooves/texture matched tothose of the spherical pedestal. In general, a pedestal having anydesired surface contour can be used together with matching magnets.

Since the platforms are detachable, means of minimizing field leakagewhen the platforms are not attached can be used and can consist offerromagnetic covers matched to the surface of the magnets.

Alternative embodiments of the same idea include a showerhead whoseheight/angular position can be adjusted, a tap whose height/angularposition can be adjusted, etc. In general, a support with an arbitrarysurface contour, capable of firmly gripping an object at a continuouslyadjustable height/angle/position can be created using such “textured”magnets.

Magnet Wiring Clip

FIG. 57 shows a magnetic clip for routing cabling, which has one or moreclips C_57_400 and a magnetic base M_57_100 to hold the cables Ca_57_410at any desired position in proximity with any object (e.g., a shelf)that is ferromagnetic, labeled F_57_300. Exemplarily, the clips may beattached to the sides of computers at any desired positions, and thecomputer cables conveniently routed.

An Unconstrained Mechanism: Carom, Billiards, and Snooker Enhanced WithMagnetics

The carom board shown in FIG. 58 has (a) magnets M_58_100 placed beneaththe board and (b) strikers S_58_310 and pieces Pi_58_300 optionally withinduction members inserted. By suitable design (e.g., hollowing out thestrikers and pieces), it is possible to have their mass be identical tothat of a piece without an induction member. The collection of strikers,pieces, and magnets constitutes a mechanism with a planarity constraint(since they have to be on the carom board), and constraints imposed bythe sides of the board. The forces exerted on the induction members bythe magnets will influence the path of the strikers and/or the piecesand thereby add variety to the game.

Variants include placing (a) magnets on the strikers and/or pieces and(b) induction members below the board, etc. The sides of the board canalso be magnetic or have induction members. Magnets and/or inductionmembers can also be placed above the board using auxiliary supports. Thepositions of the magnets can, in one embodiment, be selectable by theplayers at the start of the play and optionally changed during play. Themagnets and induction members can be of various kinds, as described inSection A. Appropriate mechanisms like strong adhesives, strong enclosedmechanical support, etc., may be necessary to make the generally brittlemagnetic materials appropriate for pieces and strikers. In general,magnets/induction members/hysteresis members can be placed on one ormore of the board surface (e.g., below it), striker, pieces, and sidesof board. The mechanism admits of all the variants using possiblyhysteresis effects, multiple autonomously magnetic interacting members,magnet/induction/hysteresis members of different geometry, etc., as perSection A.

Power control in such devices is human skill. Power Transmission Controlcan be applied, for example, in utilizing contactless striking byinduction. In such cases, the magnetic striker does not hit the piece,but glides by it, generating inductive force to move the piece.

The same ideas can be applied to billiards and snooker, and in generalany similar board game.

Extendible Tether with Induction Braking

FIG. 59 shows an extendible two-piece tether with a stationary memberSM_59_300 having one or more magnets M_59_100 (together with flux returnpaths not shown, following Section A). A moving induction memberMM_59_200 is attached to a hook H_59_310 to which a weight can beattached. Induction braking prevents excessively rapid fall of theweight. Several such tethers can be connected together by hinges to forma pseudo-elastic “cord” that extends slowly. The geometry of thestationary member SM_59_300 and moving members MM_59_200 can be otherthan shown, including telescoping tubes, etc. In one variant, stationarymember SM_59_300 is a flexible ferromagnetic tube that is magnetic inthe interior, and the moving member MM_59_200 is a rod or tightly coiled(e.g., copper) wire, which is braked by induction effects.

A variation of this is an optical workbench, which is suspended usingseveral such tethers, together with springs to limit the maximum amountof motion allowable. The induction forces will reduce the optical benchvibrations.

The mechanism admits of all the variants using possibly hysteresiseffects, multiple autonomously magnetic interacting members,magnets/induction/hysteresis members of different geometry, etc., as perSection A. With hysteresis members and multiple autonomously magneticinteracting members, rest positions emerge that can be profitably used.For example, a series of magnets on MM_59_200 can interact withSM_59_300's magnets, creating a sequence of magnetic latching positionsfor the mechanism. In effect, a linear contactless noiseless ratchetingmechanism results.

Magnetic Levitation and Induction Braking for an Aircraft

FIG. 60 shows an aircraft utilizing magnetic levitation (maglev) fortakeoff and landing. The system functions as a maglev device duringtakeoff and as an electromagnetic brake during landing. The inductionmember I_60_200 can be a mesh of conductive material in the fuselageitself. It can also be the fuselage itself, provided the aircraftaluminum is properly alloyed to have sufficient conductivity. The fieldcan be generated by a set of superconducting magnets under the runway,arranged to have the field impinge on the craft above. The direction ofthe field will in general not be exactly vertical. In such cases, weshould use only the vertical component of the field to prevent otherundesirable disturbances to the aircraft. This can be ensured bychoosing an induction member whose effective conductivity is asymmetricalong different directions (due to choice of material, geometry, etc.)and which is oriented to direct the current perpendicular to theaircraft fuselage, roughly parallel to the wings.

If the magnetic fields can be generated over 100- to 200-meterdimensions, ultra-reliable braking can be achieved due to simplicity ofoperation, compared to conventional friction brakes, air brakes, etc.

Magnetic levitation principles can be used in takeoff as follows.High-strength superconduction magnets placed on the plane can inducerepulsive forces in a large induction member beneath the runway,generating additional lift. A moving magnetic field on the runway,generated by sequentially exciting a series of superconducting magnetson the runway, can induce lift on the aircraft fuselage. In principle,the aircraft can take off and land without power.

A variant of this is an “invisible parachute” for an aircraft. Thefuselage can be arranged to have induction members appropriately shapedand oriented. If the aircraft is to brake for any reason, an externalmagnetic field can be created in the aircraft's path, causing inductionbraking. Due to the high speed, large forces can be generated by quitemodest magnetic fields, e.g., about 0.01 Tesla or less (about 200 timesthe magnetic field of the earth). Such low-strength fields over largeregions can possibly be generated by very large superconducting magnetsplaced on “rescue aircraft.” Note that the induction force isomnidirectional and will act even when the aircraft is losing altitude(it will act to slow down descent).

The mechanism admits of all the variants using possibly hysteresiseffects, multiple autonomously magnetic interacting members,magnet/induction/hysteresis members of different geometry, etc., as perSection A.

Electromagnetic Fully Flexible Manipulator

Another application of our ideas is in electromagnetic manipulators,which (1) pick up ferromagnetic objects, (2) assemble them automaticallyusing magnetic fields generated by possibly high-strengthsuperconducting magnets (or a combination of high-strength neodymiummagnets and auxiliary coils), and (3) move them to desired positionsautomatically by controlling the currents generating the fields.Translational motion can be achieved by a field that is translating inthe direction, rotational motion (e.g., a screw being tightened) byfields that are rotating, etc.

FIG. 61 shows a bin with screws being picked up, moved right (per FIG.61) by a translating magnetic field, and tightened by rotating magneticfields, all under the control of the drive control circuitry. The majoradvantage of this system is that the forces exerted on the objects beingmoved and assembled are distributed to some extent throughout the body,minimizing stress/strain at the surface and enhancing reliability. Inaddition, controlled torque can be delivered while tightening,minimizing overtightening risk. Finally, the number of degrees offreedom of the manipulator is in principle infinite, since there are nomechanical joints. This can find applications ranging from assembly ofsmall structures to assembly of high-reliability apparatus likeaircraft, high-speed trains, etc.

The mechanism admits of all the variants using possibly hysteresiseffects, multiple autonomously magnetic interacting members,magnets/induction/hysteresis members of different geometry, etc. as perSection A.

Unless explicitly stated otherwise, each numerical value and rangeshould be interpreted as being approximate as if the word “about” or“approximately” preceded the value of the value or range.

It will be further understood that various changes in the details,materials, and arrangements of the parts which have been described andillustrated in order to explain the nature of this invention may be madeby those skilled in the art without departing from the principle andscope of the invention as expressed in the following claims.

1. An apparatus, comprising: a first component having one or moreelectromagnetic elements; and a second component having one or moreelectromagnetic elements and movably coupled to the first component,wherein: the second component is adapted to move with respect to thefirst component in a cyclical manner; and the one or moreelectromagnetic elements of the first component are adapted to interactwith the one or more electromagnetic elements of the second componentduring each of one or more cycles of motion of the second component withrespect to the first component such that, when a constant force profileis applied to move the second component with respect to the firstcomponent, the speed of motion increases and decreases one or more timesduring each cycle of motion due to different levels of electromagneticinteraction between the electromagnetic elements within each cycle ofmotion, wherein: at least one of the electromagnetic elements in one ofthe components is a magnet; and at least one of the electromagneticelements in the other component is an interaction element, wherein: theinteraction element has a material that exhibits at least one ofelectrical conductivity and magnetic hysteresis; and the electricalconductivity or magnetic hysteresis or both of the material varies withposition over the interaction element, such that, as the secondcomponent moves with respect to the first component, the magnet inducesat least one of eddy currents and hysteresis forces in the interactionelement that vary in intensity during each cycle of motion.
 2. Theapparatus of claim 1, wherein the interaction element has one or morecutouts, each cutout corresponding to a position of local minimuminteraction level between the electromagnetic elements.
 3. The apparatusof claim 2, wherein the interaction element has a plurality of cutouts.4. The apparatus of claim 3, wherein at least two of the cutouts havedifferent dimensions resulting in different local minimum interactionlevels and different speeds of motion over each cycle of motion.
 5. Anapparatus, comprising: a first component having one or moreelectromagnetic elements; and a second component having one or moreelectromagnetic elements and movably coupled to the first component,wherein: the second component is adapted to move with respect to thefirst component in a cyclical manner; and the one or moreelectromagnetic elements of the first component are adapted to interactwith the one or more electromagnetic elements of the second componentduring each of one or more cycles of motion of the second component withrespect to the first component such that, when a constant force profileis applied to move the second component with respect to the firstcomponent, the speed of motion increases and decreases one or more timesduring each cycle of motion due to different levels of electromagneticinteraction between the electromagnetic elements within each cycle ofmotion, wherein said first and second components comprise a bubblevibration toy, wherein said bubble vibration toy shows oscillations ofat least one soap film stretched over one or more rigid or partiallyrigid boundaries, said oscillations being visible in a mode of motion.6. An apparatus, comprising: a first component having one or moreelectromagnetic elements; and a second component having one or moreelectromagnetic elements and movably coupled to the first component,wherein: the second component is adapted to move with respect to thefirst component in a cyclical manner; and the one or moreelectromagnetic elements of the first component are adapted to interactwith the one or more electromagnetic elements of the second componentduring each of one or more cycles of motion of the second component withrespect to the first component such that, when a constant force profileis applied to move the second component with respect to the firstcomponent, the speed of motion increases and decreases one or more timesduring each cycle of motion due to different levels of electromaaneticinteraction between the electromagnetic elements within each cycle ofmotion, wherein said first and second components are adapted to attachto an internal combustion engine, wherein the levels of electromagneticinteraction between the first component and the second component vary ina manner to partly or completely smooth out the pulsating torque beingdelivered by the combustion engine.